Layout And Design Guidelines For Boat Launching Facilities 2021.pdf

Layout & Design Guidelines for

Boat Launching Facilities

California Department of Parks and Recreation

Division of Boating and Waterways

Preface | 3

Preface

The 2021 Layout & Design Guidelines for Boat Launching Facilities (2021 Guidelines) presents a broad range of information regarding the layout, design and construction of boat launching facilities, including the 2010 ADA Standards for Accessible Design. The 2021 Guidelines will be of benefit to engineers, architects, contractors, material suppliers, manufacturers, administrators, boating facility owners and operators, maintenance personnel and the recreational boating community statewide.

The development of guidelines for boat launching facilities began in the 1960s. The first edition was created in 1968 by the Department of Harbors and Watercraft. The department became the Department of Navigation and Ocean Development in 1969, and the Department of Boating and Waterways (DBW) ten years later in 1979.

A number of subsequent guidelines were published over the ongoing years up to the present.

On July 1, 2013, DBW was merged into the California Department of Parks and Recreation under which future guidelines such as the 2021 Guidelines will be updated and improved. The 2021 Guidelines are comprehensive in the range of topics addressed including commentary that explains some of the more difficult issues. This document has been completed under the oversight of the State Parks Divisions of Boating and Waterways, and Acquisition and Development.

We wish to extend a word of thanks to those persons, agencies and organizations who participated in the process of guidelines development over the years, and to the various people who reviewed and commented on the final review draft of the 2021 Guidelines.

The 2021 Guidelines were developed under the direction and supervision of Mr. Steve Watanabe, P.E., Supervising Civil Engineer, Department of Parks and Recreation, Acquisition and Development Division and Karl Rose, P.E., Senior Civil Engineer, California State Parks, Facilities & Development Division. The author and editor is Bill Curry, P.E. (RA).

Ramona Fernandez Brian Dewey

Acting Deputy Director Assistant Deputy Director Division of Boating and Waterways Facilities and Development

4 | Special Acknowledgment

Special Acknowledgment

This latest edition of the Division of Boating and Waterways’ Layout & Design Guidelines for Boat Launching Facilities is dedicated to Bill Curry who peacefully passed away on June 6, 2020 at the age of 81. A native of Amarillo, Texas, Bill was recruited out of Texas Tech University in 1963 to work on California’s monumental State Water Project. When the project was completed in 1968, Bill moved on to the Department of Harbors and Watercraft (precursor to the Division of Boating and Waterways) where he began a very remarkable career ultimately retiring in 2002 as the Chief Engineer. Bill continued to work as a retired annuitant with DBW for many years providing significant contributions to the recreational boating community.

Recognizing the need to provide technical assistance to DBW grantees on how to properly design and construct boat launching facilities, Bill authored the first ever Layout, Design and Construction Handbook for Small Craft Boat Launching Facilities in the early 1970s. The handbook essentially codified boat launching facility design and construction in California and was extremely well-received by DBW grantees. Bill had a tremendous talent for being able to make a technical document understandable and relatable to all audiences, whether they be engineers, contractors, building officials, boat ramp operators, regulators or the general public, which is why his handbook had such universal appeal.

Besides authoring DBW’s boat launching facilities handbook, Bill also authored DBW’s Marina Berthing Facilities – Design Guidelines and DBW’s 2010 ADA Standards Excerpts for Recreational Boating Facilities, which explained how to design boat launching facilities and marinas in compliance with the Americans with Disabilities Act. A gifted engineer, Bill also designed California’s first floating restroom for boaters, which eventually led to the development of DBW’s highly successful floating restroom program.

Bill’s contributions to the recreational boating community both in California and nationally have been extensive and long-lasting. Bill also served as a commissioner on California’s Delta Protection Commission, was the 2002 recipient of the States Organization for Boating Access’ prestigious William H. Ivers Award, and was a tireless advocate for making boating facilities accessible for persons with disabilities.

Bill will be remembered as a warm and compassionate human with an extraordinary gift for making people smile with his puns; whether as a friend, colleague, mentor or source of inspiration you were lucky to have known him. Fair winds and following seas, Mr. Curry.

Bill Curry

Special Acknowledgment | 5

Contents

Introduction 9

Section A: Definitions 11

Section B: Water Areas 14

B1. Fairways 14 B1.1 Minimum Fairway Depth 14 B1.2 Minimum Fairway Bottom Width 14 B1.3 Minimum Fairway Length 14

B2. Channels 14 B2.1 Minimum Channel Depth 14 B2.2 Minimum Channel Bottom Width 14 B2.3 Channel Markers 14

B3. Signs and Waterway Markers 15 B3.1 Swimming Areas Adjacent To Launching Ramps 15 B3.2 Waterway Markers 15

Section C: Launching Ramps 16

C1. General Requirements 16 C1.1 Launching Ramp 16 C1.2 Minimum Widths of Launching Lanes 16 C1.3 Number of Launching Lanes 17 C1.4 Arrangement of Launching Lanes 17 C1.5 Design High and Design Low Water Elevations 18 C1.6 Length of Launching Ramps 19 C1.7 Launching Ramp Slopes 19 C1.8 Launching Ramp Vertical Curves 20 C1.9 Launch Ramp Aprons, Approach, Turning Patterns, and Turn-Around Area 20 C1.10 Turn-Around Areas on Launching Ramps 22

C2. Construction Details, Materials and Procedures 23 C2.1 Cast-in-Place Concrete Launching Ramps 23 C2.2 Precast Concrete Panels 24 C2.3 Cellular Concrete Mats 26 C2.4 Concrete Push Slabs 27

6 | Special Acknowledgment

C2.5 Concrete Mix Specifications for Launching Ramps 28 C2.6 V-Groove Launching Ramp Finish Details 28 C2.7 V-Groove Tool Design and Fabrication 30 C2.8 V-Groove Launching Ramp Construction Procedure 30 C2.9 Construction Joints 31 C2.10 Weep Holes 31 C2.11 Erosion Control Features 32

Section D: Boarding Floats 33

D1. General Requirements 33 D1.1 Width Requirements 33 D1.2 Length Requirements 35 D1.3 Height Requirements 35

D2. Loading Design Criteria 36 D2.1 Dead Load Only (DLO) 36 D2.2 Uniform Live Loads (ULL) 36 D2.3 Live Point Loads (LPL): 37 D2.4 Freeboard 38 D2.5 Wind, Wave, Current and Impact Loadings 38 D2.6 Deflections 39 D2.7 Gangplank and Gangway Loadings 40

D3. Design Details 40 D3.1 Hardware 40 D3.2 Decking 42 D3.3 Pontoons 43 D3.4 Fender Boards 44

D4. Types of Boarding Float Systems 45 D4.1 Non-Floating Boarding Platforms 45 D4.2 Suspended Non-Floating Boarding Platforms 45 D4.3 Pile-Guided Articulated Boarding Floats/Fixed Abutment 46 D4.4 Cable-Guided Boarding Floats 47 D4.5 Single-Rail Guided Boarding Floats 48 D4.6 Dual-Rail Guided Boarding Floats 49

D5. Abutments 52 D5.1 General Requirements 52 D5.2 Design Details 53

D6. Guide Piles 54 D6.1 General Requirements 54 D6.2 Design Details 55

Special Acknowledgment | 7

D7. Pile Yokes 56 D7.1 General Requirements 56 D7.2 Exterior Pile Yokes 57 D7.3 Interior Pile Yokes 58 D7.4 Pile Yoke Rollers and Rub Strips 60 D7.5 Pile Yoke Design Details 61 D7.6 Pile Yoke and Boarding Float Rotation 63

D8. Gangplanks 66 D8.1 General Requirements 66 D8.2 Accessible Gangplanks 66 D8.3 Design Details 69

D9. Gangways 70 D9.1 General Requirements For Application At Boat Launching Ramps 70 D9.2 Gangway Minimum Uniform Live Loads (ULL) 72 D9.3 Gangway Minimum Width 72 D9.4 Gangway Railings 72 D9.5 Gangway Decking 73 D9.6 Maximum Gangway Slopes 74 D9.7 Gangplanks Provided at the Lower and/or Upper Ends of a Gangway 74 D9.8 Transition Plates 74 D9.9 Boarding Floats and Gangway Landings 75 D9.10 Accessible Gangways 75

Section E: Shoreside Facilities 77

E1. Parking Facilities 77 E1.1 Types of Boat Launching Facilities Parking Spaces 77 E1.2 Location of Parking Spaces 79 E1.3 Minimum Number of Parking Spaces 79 E1.4 Minimum Parking Space Dimensions 79 E1.5 Parking Lot Finish Grades 81

E2. Accessible Parking Spaces (Barrier-Free Parking) 81 E2.1 General Requirements 81 E2.2 Minimum Number of Accessible Parking Spaces 82 E2.3 Minimum Dimensions and Layout Factors 83 E2.4 Access Aisles 85 E2.5 Parking Space Signs and Pavement Markings 88

8 | Special Acknowledgment

E3. Roadways and Parking Areas 91 E3.1 Access Roads 91 E3.2 Parking Lot Driveways 92 E3.3 Parking Lot Pavement Design Considerations 93 E3.4 Unpaved Parking 94

E4. Restroom Facilities 94 E4.1 General Requirements 94 E4.2 Public Health and Accessibility Requirements 95

E5. Utilities 96 E5.1 Potable Water 96 E5.2 Oil Recovery and Sewer Systems 96 E5.3 Area Lighting 96 E5.4 Overhead Electrical Powerlines 97

E6. Signs 98 E6.1 Types of Signs 98 E6.2 Location, Orientation and Legibility 100 E6.3 Size of Signs 100 E6.4 Design Details 101

Appendix A: Commentary 102 Appendix A: Commentary – Section C 103 Appendix A: Commentary – Section D 130 Appendix A: Commentary – Section E 148

Appendix B: 2010 ADA Standards – Recreational Boating Facilities 162

Appendix C: 2019 California Building Code 163

Introduction | 9

Introduction

The primary purpose of the 2021 Layout & Design GUIDELINES for Boat Launching Facilities is to provide technical assistance and direction for planning, design and construction. Recreational boat launching facilities are funded under Local Assistance and Capital Outlay programs administered by the California Department of Parks and Recreation Division of Boating and Waterways (DBW), and Acquisition and Development, Boating Facilities Unit.

The GUIDELINES address typical conditions and are not intended to be all inclusive or absolute. Unique site conditions and circumstances may require special analysis, applications and design considerations not addressed herein. Special care and attention should always be applied to each project to ensure excellent design, the most appropriate selection of materials, and a boat launching facility that is safe, functional, attractive, durable and sustainable over the design life of the project.

The information in these GUIDELINES is useful for recreational boating facility issues in general, and will be helpful to anyone involved in the development of both new and altered boating facilities.

These GUIDELINES do not address site selection considerations for new boat launching facilities, or site considerations for expansion of existing facilities. Also, environmental practices, fish cleaning stations, boat engine oil recycling facilities, collection of solid waste materials, and permitting issues are beyond the scope of this document.

In the presentation of design and construction criteria, the following convention is used:

§ Criteria printed in “standard type” are recommended general criteria; and

§ Criteria printed in “bold italics type” are minimum safety criteria.

It is recognized that in certain isolated instances the application of minimum safety criteria may not be feasible, desirable or even possible. A better alternative may very well exist at a given site that will not jeopardize safety and is judged to be equal to or better than the minimum criteria presented herein. Deviations from the minimum criteria will be considered on a case-by-case basis jointly by the project owner, DBW Grants and Loans Unit Manager, Boating Facilities Unit, and the permitting agency(s) issuing the building permit(s). Individual project owner/operators will bear the responsibility to clearly document the rationale for any deviation(s).

10 | Introduction

It is not intended that deviations from either the recommended general criteria or the minimum safety criteria be used to justify wholesale departures from the advice, direction, experience and criteria presented herein. To varying degrees, these GUIDELINES represent the collective experience, wisdom and advice of boaters, harbormasters, material suppliers, designers, engineers, architects, consultants, contractors, government officials, and various other persons and groups representing both public and private interests compiled over a period of five decades from the late 1960s to the present. The intent is that these updated GUIDELINES will be a reliable guide for the planning, layout, design and construction of boat launching facilities.

These GUIDELINES may be viewed and/or downloaded from the web site indicated below. It is requested that the GUIDELINES be used as a complete document, and not be edited, altered or changed in any way from its officially published form.

DBW Publications:

http://dbw.parks.ca.gov/?page_id=28827

Should you wish to submit comments, corrections and/or suggestions to be considered for future editions of these GUIDELINES, contact Karl Rose P.E. as indicated below.

California State Parks Facilities & Development Division One Capitol Mall, Suite 410 Sacramento, CA 95814

(916) 812-0358 info@parks.ca.gov

COMMENTARY FLAGS

The “Flag” symbol seen in the right margin beside this paragraph will be seen beside various sections and sub-sections throughout Sections C, D and E of these GUIDELINES. A notification “flag” indicates that commentary is provided in Appendix A on the particular section, subject and topic flagged.

The individual Appendix A commentary headings refer back to specific sections and sub-sections flagged in Sections C, D and E, providing a two-way reference system.

Section A: Definitions | 11

Section A: Definitions

Color Key to Defined Terms:

Definitions in:

ALL CAPS BOLD BLACK PRINT are stand-alone definitions ALL CAPS BOLD ITALICIZED RED PRINT are headings for sub-sets of related definitions; and lower case bold indented underlined blue print are sub-set definitions under a heading.

ABUTMENT a fixed wedge-shaped structure at the head of a launching ramp to which stationary boarding floats are hinged, and which provides pedestrian access between shore and the boarding floats

BOARDING FLOAT a platform-type structure, either floating or fixed, stationary or adjustable, located immediately alongside of or on a launching ramp, designed for short term moorage of boats and facilitation of pedestrian access to and from boats in the water

DOCK a platform, either floating or fixed, provided at a boat launching facility for the temporary securing of a boat to facilitate pedestrian access to and from the boat [synonymous with BOARDING

FLOAT]

CHANNEL a waterway, natural or artificially dredged, that is delineated, operated and maintained for the safe passage of boats between a boat launching ramp and the main waterbody upon which the primary boating activities occur entrance channel a watercourse, external to a boat launching facility basin, marina basin, etc., through which boats travel between the facility and the water body where the primary boating activities occur interior channel a watercourse, within a boat launching facility basin, marina basin, etc., through which boats travel between the facility and an entrance channel

COURTESY DOCK a dock (not on a launching ramp) that is accessible via a gangway, which together typically form an “L” or “T” shape configuration

12 | Section A: Definitions

DESIGN HIGH WATER a selected high water level based on hydrologic data and other appropriate records, which is used as a safe and practical upper limit for the design and construction of a launching ramp

DESIGN LOW WATER a selected low water level based on hydrologic data and other appropriate records, which is used as a safe and practical lower limit for the design and construction of a launching ramp

FACILITY all or any portion of buildings, structures, site improvements, elements, pedestrian routes and vehicular ways located on a boat launching site

FAIRWAY bay, lagoon, basin, watercourse or other waterway into which a launching ramp extends for the launching and retrieval of boats

FREEBOARD vertical height from the water surface to the top of the deck of a boarding float or dock, measured under various loading conditions [dead load only, live+dead load...)

GANGPLANK a 5% maximum slope platform or bridge, without guard rails and handrails, that provides pedestrian access between the sloped surface of a boat launching ramp and a boarding float that is not attached to an abutment (i.e., a cable guided or rail guided boarding float, or a pile guided boarding float designed to ride high on piles in flood waters)

GANGWAY a variable-sloped pedestrian walkway that links a fixed structure or land with a boarding float (gangways that connect to vessels are not included in this definition)

GUIDE PILE a vertical pile within a pile yoke that holds the boarding float on location, and allows it to rise and fall with changing water levels

HIGH WATER the extreme high water level projected to occur at a launching ramp site

LOW WATER the extreme low water level projected to occur at a launching ramp site

LAUNCHING RAMP an inclined surface consisting of one or more launching lanes extending down into a fairway, and upon which trailered and other watercraft are launched into and retrieved from a waterbody apron a dedicated maneuvering area serving as a transition between parking area driveways and a launching ramp

Section A: Definitions | 13 head of ramp the upper end of a launching ramp launching lane a clearly delineated longitudinal section of a launching ramp, designed to accommodate the launching or retrieval of one boat at a time slope of ramp the percent slope of a launching ramp determined by dividing the vertical drop by the horizontal projection, and multiplied by 100 [a 15% ramp drops 15 ft vertically each 100 ft horizontally] toe of ramp the lower end of a launching ramp turn-around area an area of expanded overall width of a long launching ramp to facilitate turning vehicles and trailers around in preparation for launching and/or retrieving boats, and to minimize the backing distance when launching a boat at low water

PILE YOKE a frame, ring or other structural device attached along the side of a boarding float, or a framed opening in a boarding float, through which a guide pile passes and keeps the boarding float in a specific location

TOE PLATE a sloping pedestrian walkway surface that provides a smooth and even transition between the sloping surface of a boat launching ramp and a gangplank

TRANSITION PLATE a sloping pedestrian walkway plate that provides a smooth and even transition between a gangway and shore, and/or between a gangway and a floating dock

V-GROOVE the saw-tooth pattern usually imparted diagonally across the surface of a concrete boat launching ramp to provide traction for vehicles launching and retrieving trailered boats

VERTICAL CURVE a circular crest curve in the vertical profile at the upper end of a launching ramp that provides a smooth transition between the relatively level slope of the apron and the fixed slope of the launching lanes

14 | Section B: Water Areas

Section B: Water Areas

B1. FAIRWAYS

B1.1 Minimum Fairway Depth

4 ft below design low water (DLW) (includes depth for buildup of siltation; see Section C1.6.3 on page 19)

B1.2 Minimum Fairway Bottom Width

Not less than the combined width of the launching ramp and riprap shoulders or other shore protection provided immediately adjacent to the sides of the launching ramp.

B1.3 Minimum Fairway Length

B1.3.1 50 ft beyond toe of ramp at design low water (DLW).

B1.3.2 Fairway shall be clear of navigational hazards and obstructions.

B2. CHANNELS

B2.1 Minimum Channel Depth

4 ft at design low water (DLW)

B2.2 Minimum Channel Bottom Width

75 ft

B2.3 Channel Markers

In cases where channels are constructed through lowlands or tidal areas which are periodically submerged, such channels should be marked with appropriate launching ramp fairway minimum fairway length and depth minimum channel depth and bottom width

Section B: Water Areas | 15 navigational aids such as buoys, piles, lights or other devices in accordance with the California Waterway Marker System.

B3. SIGNS AND WATERWAY MARKERS

B3.1 Swimming Areas Adjacent To Launching Ramps

B3.1.1 Adjacent swimming areas and boat launching facilities shall be clearly delineated and separated by:

■ signs;

■ barrier fences;

■ walls;

■ piers;

■ breakwaters;

■ log booms;

■ buoys and buoy lines;

■ piles;

■ lights; and/or

■ other appropriate devices.

B3.1.2 Such barriers and warning devices shall extend out into the water a distance not less than the recognized extent of the swimming area(s) under all water level conditions when boat launching and swimming occur.

B3.2 Waterway Markers

Where adjacent boat launching facilities and swimming areas exist, both activity areas shall be identified by highly visible weather resistant signs and waterway markers installed on both the shore and on floating barriers.

Warning devices must be provided where necessary. Signs and waterway markers shall be in accordance with the California Waterway Marker System.

no swimming sign at end of float examples of waterway marker buoys and signs

16 | Section C: Launching Ramps

Section C: Launching Ramps

C1. GENERAL REQUIREMENTS

C1.1 Launching Ramp

A launching ramp typically consists of one or more concrete launching lanes and boarding floats. The overall width of a launching ramp includes the launching lanes and the concrete slab under the boarding floats for support of the floats when they come to rest at low water.

C1.2 Minimum Widths of Launching Lanes

C1.2.1 Multiple-Lane Launching Ramps

C1.2.1.1 Minimum launching lane width shall be not less than 15 ft.

C1.2.1.2 The minimum launching lane width includes the width of 3-inch wide “shiny edge” troweled finishes along the edges of launching lanes, but not the width of raised curbs. A full minimum 15-ft launching lane width must be provided for maneuvering vehicles and trailers while launching and retrieving boats.

C1.2.1.3 Delineate each launching lane with a standard 3-inch wide shiny edge finish along the following edges:

■ across the top edge (head of ramp);

■ down both longitudinal edges; and

■ across bottom and top edges of planned transverse construction joints

C1.2.2 Single-Lane Launching Ramps

C1.2.2.1 Single-lane launching ramps up to 50 ft in length shall have a minimum width of not less than 16 ft.

multiple launching lanes

3-inch shiny edge finish

Section C: Launching Ramps | 17

C1.2.2.2 Single-lane launching ramps over 50 ft in length are recommended to be 20 ft wide.

C1.3 Number of Launching Lanes

C1.3.1 One launching lane will generally handle up to 50 boat launchings and 50 boat retrievals per day at a well designed and operated facility.

C1.3.2 The number of launching lanes at a given site will be determined by user demand and the characteristics of the site.

This will vary between urban and rural locations, the primary type(s) of boating that occurs on a specific waterbody, vehicle parking capacity, the seasonal drawdown of the waterbody and the length of the launching ramp.

C1.4 Arrangement of Launching Lanes single-lane launching ramp two (2) pairs of launching lanes

8 lane launching ramp with 2 pairs of three adjacent boat launching lanes bordered by 2 single lanes

C1.4.1 Factors that influence launching lane arrangements include:

■ number of launching lanes;

■ presence of boarding floats between launching lanes;

■ length of the launching ramp; and

■ alignment of the launching ramp relative to entrance and exit driveways.

C1.4.2 On multiple launching lane ramps, the lanes should be arranged in pairs. A two-lane launching ramp with boarding floats located along both outside edges is the most common basic boat launching facility. Larger launching facilities should consist of even numbered pairs of launching lanes, i.e., 4-lanes, 6-lanes, etc.

C1.4.3 Launching ramps with three adjacent launching lanes should usually be avoided. Boats launched in the center lane would not have direct access to a boarding float. However, for operational, safety and boat traffic reasons, a boat launching facility (in a large marina) that has three adjacent launching lanes provides a wide emergency access for fire boats, fire trucks and equipment in the event of a burning boat and/or dock.

18 | Section C: Launching Ramps

C1.4.4 An unusual arrangement is a two-lane launching ramp with one lane designated for use by powerboats, and the other lane for non-motorized boats such as kayaks, canoes and inflatables. The powerboat launching lane should be finished with typical 1 inch V-grooves to provide adequate traction for vehicles launching and retrieving powerboats. However, 1/2 inch V-grooves should be used on the surface of the non-motorized boat launching lane. The smaller grooves are more “bare-foot-boater friendly” for the users, and vehicle traction is not a problem for launching and retrieving non-motorized boats.

two-lane launching ramp 1 inch V-grooves on right lane 1/2 inch V-grooves on left lane rowing shell being hand-launched minimum toe of ramp water depth

C1.5 Design High and Design Low Water Elevations

C1.5.1 It is recommended that at least 25 years of reliable water level data be used to establish design high and design low water for new launching ramps. If reliable water level data is not available, confer with local city and county officials, water agencies, districts, law enforcement officers, search and rescue organizations, newspapers and television/radio stations. Input from nearby land owners and long-term residents can also be of great value by providing their experiences, observations and photos that have day, month and year notations.

C1.5.2 Boat launching facilities located on waterways subject to future sea level rise (SLR) must be planned to anticipate increased design high water levels. Documents are being developed under the direction of the California Ocean Protection Council (OPC) for guidance to incorporate SLR projections into planning and construction of future shoreline projects, including boat launching facilities. The science of future SLR is evolving. The amount and rate of future SLR will be subject to periodic adjustments for many years to come. For current SLR projections and information on this matter, go to: www.opc.ca.gov. BLF projects funded by DBW must be designed for a minimum of 20 years of SLR after construction is completed.

http://www.opc.ca.gov

Section C: Launching Ramps | 19

C1.6 Length of Launching Ramps

C1.6.1 The actual length of a launching ramp is determined by the following:

■ design high and design low water elevations;

■ launching ramp head and toe elevations;

■ launching ramp design slope; and

■ site topography.

C1.6.2 The head-of-ramp elevation should be a minimum of 1 ft above design high water.

C1.6.3 The toe-of-ramp elevation should be minimum of 3 ft below design low water.

C1.7 Launching Ramp Slopes

A launching ramp is usually a uniform slope beginning where it joins to the lower end of a vertical curve immediately above the ramp slope, and ends down slope at the toe of the ramp.

C1.7.1 Range of Launching Ramp Slopes Max. Slope: 15% Min. Slope: 12% 15 ft V to 100 ft H 12 ft V to 100 ft H

1:6.67 1:8.33 range of launching ramp slopes vertical curve at head-of-ramp

C1.7.2 The slope of a launching ramp should be uniform throughout its length. If necessary to alter the slope at some point down the ramp, the slope change should be from a flatter slope to a steeper slope. Going the other way from a steeper slope to a flatter slope forms a shallow valley on the launching ramp that may cause the skeg on an outboard engine locked in the down position to strike the ramp surface when launching and retrieving a boat. It may also cause tensioned cables on cable-guided float systems to be suspended above the launching ramp surface. In either case, the change in slope should be made with a long vertical curve to provide a safe and comfortable transition between the two slopes. The greater the change, the greater the potential problems.

20 | Section C: Launching Ramps

C1.8 Launching Ramp Vertical Curves

C1.8.1 Provide a 20 to 25 ft vertical curve in the launching ramp apron to provide a smooth and safe vehicle-trailer transition between parking area driveways and the 12% to 15% launching ramp slope. This provides a uniform slope throughout the ramp length, and eliminates potential problems with the functioning of boarding floats, gangplanks and boarding float guidance systems. If DHW is within the vertical curve, provide v-groove starting at 1 ft higher than DHW.

C1.8.2 At salt water coastal locations, full width launching ramp aprons 60 to 80 ft long should be of reinforced concrete construction rather than paved with asphalt concrete (AC). Under continuous exposure to vehicle and trailer wheel loads, and salt water dripping from boats and trailers just removed from the water, AC paving has not proved to be as durable as concrete.

C1.9 Launch Ramp Aprons, Approach, Turning Patterns, and Turn-Around Area

C1.9.1 A launching ramp apron must be provided at the head of a launching ramp. The apron functions as a transition area between the driveways, the parking areas, and the launching ramp. It also serves as a maneuvering area where boaters can position their vehicles and trailers to line up with particular launching lanes in preparation for launching and retrieving their boats.

C1.9.2 All other factors being equal, the initial approach to the launching ramp should be in a counter-clockwise pattern. This rotation will: (1) keep the trailer in full view in the driver’s sideview mirror; (2) greatly assist in achieving alignment with a launching lane; (3) enhance safety for vehicles, drivers and pedestrians; and (4) be helpful to drivers who are not proficient at backing boat trailers.

launching ramp apron merging with vertical curve benefits of counter-clockwise turning

C1.9.2.1 To impose a clockwise turning pattern dictates that during the initial approach to the launching

Section C: Launching Ramps | 21 ramp, the trailer will be out of the driver’s sideview mirror for much of the maneuvering operation. However, on large multi-lane launching ramps of six to ten adjacent launching lanes uninterrupted by boarding floats, and with vehicle access from two or more directions, this may be a moot point. Such expansive launching ramp areas provide maximum flexibility in using the facilities, but on busy boating days during the summer boating season it can also lead to chaos and lack of organized traffic flow.

C1.9.2.2 At smaller launching facilities with four or less launching lanes, a counter-clockwise traffic pattern should be utilized unless local conditions, land configuration and/or the location and alignment of existing entrance roads dictates otherwise.

C1.9.3 The size and configuration of a turn-around area will be dictated by the layout of the launching ramp relative to entrance and exit access roads, the location of vehicle-trailer parking areas, and the direction from which vehicles pulling trailers will approach the launching ramp.

C1.9.4 A minimum 60 ft diameter turn-around area immediately above a launching ramp apron is recommended. Most automobiles, pickup trucks, SUVs and RVs pulling recreational boat trailers will be able to negotiate 360 degree turns within a 60 ft diameter circle.

C1.9.5 In cases where access roadways to a launching ramp are parallel to and near the shoreline, it may be difficult to provide both a turn-around area and ramp apron between the roadway and the head of the launching ramp. In such cases, a “cross” shaped layout can work, providing for thru-traffic flow, a turning area, and accommodation for both clockwise and counter-clockwise traffic patterns. For example, counter-clockwise vehicle-trailer traffic would approach the top left side of the launching ramp, turn 90 degrees counter-clockwise to the left away from the shoreline, line up with a launching lane, back up across the access roadway and ramp apron, and proceed down the launching ramp. The entrance and exit roadways form the arms of the “cross” providing entrance from one side of the launching ramp and exit out the other side. The “vertical leg” of the “cross” must be long enough to provide: “cross” shaped turn-around area

22 | Section C: Launching Ramps

■ for 90 degree turns away from the shoreline (30-40 ft);

■ the length of a vehicle and trailer for alignment with a launching lane (up to

65 ft for an RV with trailer);

■ the width of the thru-traffic access roadway; and

■ the length of the apron down to the head of the launching ramp. Measured from the head of ramp, the length of the “vertical leg” of the cross can be up to 150 ft.

C1.9.6 The launching ramp apron should be constructed of the same reinforced concrete as used for launching ramps. Aprons are sometimes used as boat-ready areas during launching and retrieval of boats. The apron will be continuously wet during busy use periods, and subjected to erosive dripping of water and debris from wet trailers and boats. AC paved aprons have not proven to be durable under these conditions, particularly on coastal saltwater launching ramp aprons.

They erode and break down rather rapidly requiring repair, resurfacing and/or replacement more frequently than more durable concrete aprons.

C1.10 Turn-Around Areas on Launching Ramps

C1.10.1 A turn-around area is an expansion in the clear overall width of a long launching ramp to facilitate turning vehicles and trailers around in preparation for launching and/or retrieving boats. The primary purpose of a turn-around area is to minimize vehicle/trailer backing distances during low water periods.

C1.10.2 Where possible to do so, a turn-around area shall be provided at 200 ft maximum intervals, be a minimum of 60 ft in diameter, and be finished with the same V-groove ramp finish as the launching lanes.

turn-around area dimensions

C1.10.2.1 Launching ramps with at least four (4) adjacent launching lanes totaling a minimum clear width of not less than 60 ft do not require designated turn-around areas. Such launching ramps are wide enough for most vehicles pulling boat trailers to turn around at any point along the length of the launching ramp.

C1.10.2.2 A turn-around area should not interrupt the clear delineation of launching lanes above, through and below the turn-around area.

Section C: Launching Ramps | 23

C2. CONSTRUCTION DETAILS, MATERIALS AND PROCEDURES

C2.1 Cast-in-Place Concrete Launching Ramps

Cast-in-place launching ramps constructed with reinforced concrete is the primary method of launching ramp construction because of the monolithic nature of the completed launching ramp, its strength and durability, and relative ease of construction. It is the method that should be used unless local conditions dictate the use of precast panels or push slabs.

C2.1.1 Cast-in-place concrete slabs can be constructed “in-the-dry” or by “de-watering” in both fresh and salt water. De-watering may occur naturally in lakes and reservoirs subject to seasonal water level drawdowns. De-watering of river and coastal sites can be accomplished through the use of cofferdams.

C2.1.1.1 The same minimum launching ramp slab thickness and rebar cover dimensions should be used in both fresh and salt water environments in consideration of possible settlement, cracking, inaccurate placement of steel reinforcement, poor inspection, and an expected 20-year launching ramp service life.

■ Minimum slab thickness: 8 inches > measured from bottom of V-grooves to bottom of slab

■ Minimum concrete cover: 3 inches > measured from top of rebar to bottom of finished V-grooves, and > measured from bottom of rebar to bottom of concrete slab.

C2.1.1.2 Cast-in-place launching ramp slabs are to have an actual 8 inch thickness rather than a nominal thickness. The use of form lumber with nominal width dimensions that are less than design slab thicknesses will not result in meeting the minimum concrete slab thickness and rebar cover requirements. For example, the use of nominal dimension 2 inch x8 inch lumber will result in a finished slab only about 7-1/2 inch thick, or less. This would result in almost a 10% reduction in the thickness of the slab.

C2.1.1.3 #4 minimum steel reinforcement (1/2 inch diameter) is to be used on 12 inch centers, both ways. This constitutes temperature steel, but it may not be structurally adequate to support the loads that will occur during the service life of all concrete launching ramp slabs. Slabs must be designed for site specific conditions and constructed in compliance with the design plans and specifications. The rebar must be blocked up on dobies in the forms to minimum slab thickness

24 | Section C: Launching Ramps ensure that the final position of the rebar is at the center of the slab depth such that the required 3 inch cover, top and bottom, is provided. Care must be taken to prevent concrete workers from stepping on and dislocating the rebar in the forms prior to and during placement of the concrete.

C2.1.1.4 Epoxy coated rebar is often recommended for use in salt water launching ramp slabs to guard against salt water corrosion of the steel.

However, it must be kept in mind that epoxy coatings are vulnerable to scrapes and cuts that can occur during the construction process, subjecting the steel to corrosion along the inside of the external epoxy coating.

C2.1.1.5 Reinforced concrete cutoff walls, not less than 6 inches thick and 24 inches deep measured from the top of the launching ramp surface, should be provided along the head, toe and outside edges of cast-in-place launching ramp slabs unless site soil conditions dictate otherwise. In highly erodible soils, cutoff wall depths may have to be increased up to 36 inches to guard against undercutting during storms and floods. In durable rock foundation material, the cutoff wall depth will have to be determined as directed by the design engineer.

C2.1.1.6 Cutoff walls and launching ramp slabs should be built monolithically during the same placement of concrete.

Cold joints between the cutoff walls and the launching ramp slab should not be permitted.

C2.2 Precast Concrete Panels

C2.2.1 Precast concrete panels are useful at locations where sites cannot be completely dewatered. They are particularly useful for:

■ coastal applications subject to daily tides;

■ low-water launching ramp extensions in lakes and reservoirs;

■ remote locations where cast-in-place construction is infeasible; and

■ temporary launching ramps that can be removed from time to time.

reinforced cutoff walls flood water undercut launching ramp large precast concrete panels being placed

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Precast concrete panels are typically 3 to 5 ft wide and 8 inches thick. Precast panels are cast upside-down on a form liner that creates the v-groove texture. A launching ramp designed to have two adjacent launching lanes each 15 ft wide, and 8 ft wide boarding floats along both outside edges, would require precast concrete panels 46 ft long (8 ft + 15 ft + 15 ft + 8 ft = 46 ft). Concrete panels 8 inches thick weigh about 100 pounds per square foot of surface. Therefore, panels 3 to 5 ft wide will weigh from 13,800 to 23,000 pounds. The panels would have to be designed to withstand lifting and handling stresses during manufacture, storage, curing, shipping and final placement at a project site.

C2.2.2 The minimum 3 inch concrete cover above and below the rebar for protection of the reinforcing steel in precast panels is the same as cited for cast-in-place concrete installations in both fresh and salt water. See C2.1.1.1.

C2.2.3 To ensure the long-term alignment and stability of precast concrete panels, cast each panel with a continuous male key along the upslope edge, and a female key along the downslope edge. The male key centered in the middle of the panel edge is stronger and less vulnerable than the flanges of the female key. This method helps to avoid breakage of the keys.

C2.2.4 Precast concrete panels are subject to undermining. Therefore, the panels must be protected with a 3 to 5 ft wide perimeter of riprap, gunite, geotextile fabrics, and/or other means of durable and reliable erosion protection. The depth of the perimeter protection should be not less than twice the thickness of the precast panels, which would typically be 16 inches minimum. This is a minimum thickness for erosion protection; actual wave conditions at the site shall be considered during design and an appropriate layer thickness of erosion protection shall be incorporated in the design.

C2.2.5 Installation of precast concrete panels can effectively be accomplished using steel skid rails. The rails can be steel channels, beams or recycled railroad rails. All of the skid rails must be in the same plane at the design slope, accurately aligned and securely anchored in compacted rock base.

precast concrete panel keys ramp joint orientation

C2.2.5.1 Skid rails shall include rail stop at the bottom end of the skid rail.

Rail stops shall be welded or securely attached to the skid rail at a 90 degree angle. Rail stops shall be aligned accurately to ensure the bottom edge of precast panels are located and aligned properly.

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C2.2.5.2 Skid rails can be installed independently or as part of a prefabricated framework. If independent rails are used, they should be permanently left in place under the panels. If they are pulled out from under the panels after construction, two negative results can occur:

■ disturbance of the rock base and the panels; and

■ creation of voids under the panels that act as conduits for movement of water resulting in gradual erosion under the precast panels.

C2.2.6 In new construction that includes both cast-in-place concrete and precast panels, the panels should be placed beginning at the lower end of the skid rails, followed by construction of the cast-in-place concrete upslope from the panels. This construction sequence allows the cast-in-place concrete to be placed against and keyed into the upper edge of the top precast panel, providing a smooth seamless joint between the two types of construction.

C2.2.7 If the upper cast-in-place concrete section must be constructed first, locate the bottom edge so that a cast-in-place concrete closure section can be provided between the upper slab and the precast panels. The closure section should be approximately the width of the precast panels, be rebar reinforced, have continuous rebar through the common joint with the upper slab (at least 20 rebar diameters), and finished with the same V-groove pattern used on the cast-in-place upper slab.

completed closure section closure section under construction

C2.3 Cellular Concrete Mats

Cellular concrete mats are another option for providing boat launching ramps or extending existing launching ramps. Individual concrete blocks are connected together with cables to create mats that are installed as a unit onto a prepared foundation.

flexible cellular concrete mat upramp view downramp view

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C2.3.1 To support wheel loads, cellular concrete mats shall have a minimum thickness of 6-inches.

C2.3.2 Cellular concrete mats shall not have voids in the block face. Gaps are allowable between adjacent blocks to allow articulation.

C2.3.3 Cellular concrete mats shall be designed with a minimum 30-year service life.

C2.3.4 Cellular concrete mats shall include continuous anchoring along the upper and lower edges; anchoring within the field may be required based on site conditions

C2.4 Concrete Push Slabs

C2.4.1 At some locations it may be feasible and advisable to build launching ramps utilizing 8 inch thick concrete push slabs up to 50 ft wide and 75 ft long.

Factors to be considered are:

■ the total dead weight of the push slab;

■ the launching ramp slope; and

■ the size of track-type tractors available to push the slab.

C2.4.2 Push slabs are built on a temporary compacted earth ramp in alignment with and immediately up slope above the design location of the completed launching ramp slab. After the slab has cured, it can be pushed down the slope into the water to its final location, utilizing one or more track-type tractors.

C2.4.3 A rail-guided push slab must have guiderails properly spaced to effectively guide the push slab, and accommodate the width of a large tractor(s) capable of breaking the push slab loose and pushing it downslope into the water.

C2.4.4 A rail stop be provided at the bottom end of each guiderail, similar to what is used in precast panel construction. This is particularly important at sites where seismic activity will occur. The first push slab can then be pushed to within a few inches of the rail stop and halted to allow for inspection in the water to ensure that all rock has been cleared from between the lower edge of the push-slab and the rail stop. The push slab can then be gently pushed down the slope until it comes into full contact with the rail stop.

C2.4.5 Guiderail shall include legs anchored into the ground to prevent movement of the guiderail during the ramp pushing operation. Legs shall be 24 to 36 inches long and shall be welded to each guiderail at the top and bottom of the guiderail. The anchor legs will be vertical and the guide rails will be at the design slope of the launching ramp. Thus, the anchor legs will be welded to the guide rails at an angle dictated by the design slope of the launching ramp.

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Leg A (upper leg): Weld a leg under the upper end of each guiderail, with guiderails and anchor legs positioned not less than 12 inches upslope from the upper end of the push slab forms.

Leg B (lower leg): Weld a leg under each guiderail not less than 2 ft upslope from the design location of the upper edge of the push slab after it has been pushed to its permanent design location.

C2.4.6 Sockets 6-8 inches long can be attached at the lower end of each guiderail and at each bottom corner of the push slab. The sockets can be fabricated of steel pipe with an internal diameter that will snugly receive lengths of 1-inch diameter Schedule 40 PVC pipe with colored flags attached at the tops. The angle of the sockets will be determined by the slope of the boat launching ramp.

C2.4.7 After a slab has been satisfactorily pushed, two choices are in view:

■ complete the launching ramp with cast-in-place concrete, or

■ construct, cure and push a second slab down against the first slab.

C2.5 Concrete mix specifications for launching ramps should include the following:

■ 6 sack concrete

■ Type II cement

■ 5% air entrainment

■ 5,000 psi compressive strength @ 28 days

■ water/cement ratio of 0.40

■ 3 to 4 inch slump

■ 3/4 inch maximum aggregate.

These concrete mix specifications are based on actual design, construction and operational experience on boat launching ramp projects built over the past 40+ years. They provide a contemporary concrete mix that is easy to work, will readily take and hold a V-groove finish, and will result in a strong, durable, functional launching ramp with a long service life.

C2.6 V-Groove Launching Ramp Finish Details

C2.6.1 V-groove finishes are to be provided on all concrete launching ramps to ensure maximum traction for vehicles launching and retrieving boats and trailers. Particular attention is required in salt water where slick marine growth will sometimes be present. Momentary spinning of vehicle tires quickly wears away the growth on the peaks of the V-grooves and grips the launching ramp surface.

C2.6.2 V-grooves have alternating 1 inch 45 degrees faces at 45 degrees, resulting in 90 degrees peaks and valleys. Alignment of V-grooves should be as follows:

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■ 30 degrees measured from the horizontal toe of the launching ramp lanes; and

■ 60 degrees measured from the sloping sides of the launching lanes.

Care must be taken not to reverse the angles, a layout that would result in V-grooves that are too steep and diminish vehicle tire traction on the launching ramp surface.

C2.6.2.1 V-grooves larger than 1 inch are not necessary. Larger grooves do not provide better vehicle traction and can be difficult to walk on, particularly for persons with small feet such as young children.

C2.6.2.2 V-grooves smaller than 1 inch are more user-friendly to adults and children walking on a launching ramp, but they do not provide the necessary traction for vehicles. Smaller V-grooves are also less efficient in carrying silt and debris off the edge of launching ramps and lanes.

C2.6.2.3 V-grooves as small as 1/2 inch are often provided on launching ramps for non-motorized boats such as kayaks, canoes, inflatables and other small watercraft that do not require launching from a vehicle. 1/2 inch V-grooves are significantly more user friendly for barefoot boaters.

C2.6.3 V-grooves assist in “cleaning” a launching ramp surface in response to boat wakes, wind and storm waves, and rainwater running down the launching ramp. Sand, soil and other debris will tend to be carried down and off the sides of the launching lanes and launching ramp. Therefore, the direction of the V-grooves should be determined in consideration of the following factors:

■ topography of the site;

■ direction of prevailing wind, waves and currents;

■ source of sand, silt and other debris on the launching ramp;

■ presence of abutments and boarding floats on the launching ramp; and

■ number of launching lanes.

C2.6.4 On wide multiple-lane launching ramps, alternate the direction of the V-grooves from lane to lane to form a “herringbone” pattern.

1 inch V-groove launching ramp finish note 30° angle of diagonal V-grooves v-groove herringbone pattern

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Alternating directional V-grooves along with a 3-inch wide troweled shiny edge finish along the edges of launching lanes (see C1.2.1.3) provides a distinct delineation of the launching lanes.