Indian_Hill_Lookout_Repairs_Drawings.pdf

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CATWALK FRAMING, PLAN VIEW

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2"x 10" joists at 18" O.C, typical

Header joist, two 2"x 10"s, typical 5 places

4"x 4" handrail posts, typ.

Replace existing 2"x 10" with 3"x 10" header joist, continuous, typ. all around

8"x 8" Tower posts, existing, typ. 4 plcs

3"x 10" Tower Girders, existing, typ. 4 plcs

Cab beams, built up with three 2"x10"s, existing, typ. 3 plcs

2" x

6" to p ra il bo ar d

2" x

4" ra ils a t 7

O .C

4" x

4" ra il po st ty pi ca l a ll ar ou nd

4" x

4" d ia go na l r ai l br ac es , t yp . e ac h co rn er

Remove and dispose existing 2"x 10" joists, typ. 4 plcs

2" x

6" d ec ki ng , t yp . a ll ar ou nd

2"x 10" nailer, typ both faces of lookout

N.T.S.

N .T

.S

NOTE: Field verify all existing dimensions and notify Engineer of any discrepancies immediately.

SIM.

SIM.

41 FT TYPE TT-1 LOOKOUT TOWER

Technical Services Staff Officer

CATWALK FRAMING DETAILS

Approved:

Date: DRAWING NO.

SHEET 1 Of 5

PLAN SET _ OF _

15'4" x 15'4" CAB

CATWALK AND HANDRAIL FRAMING,

ELEVATION VIEW

NON-TRAPDOOR AND OPOSING SIDES

2"x 6" top rail board 2"x 4" rails at 7" O.C.

4"x 4" rail post, typical all around

4"x 4" diagonal rail braces, typ. each corner

2"x 6" decking, typ. all around

Notes:

1. All structural or framing lumber shall be pressure treated Douglas Fir-Larch No. 1 & Better or Select Structural.

2. Malleable iron washers will be used at each exterior face for all bolted connections.

3. All joist to header joist connections and header joist to header joist or cab beam connections shall be made with Simpson Strong-Tie Double Shear Joist Hangers, or equivalent. Where a handrail post is tangent to both members at a connection, a joist hanger will not be used. The handrail post will be connected at each face with two 2 1/2" dia. split rings with 1/2" dia. bolts.

4. Header joists for catwalk that bear on tower girders shall be secured with two angle plates, L 3 1/2 x3 1/2 x 1/4 by 16" long, with two 2 5/8" shear plates per face using 3/4" bolts. The 6" faces of the angle plates shall be placed against the tower girder. Where a handrail post is tangent at a connection to both the header joist and the tower girder, there will only be one angle plate, on the opposing face. The handrail post will be connected at each face with two 2 1/2" dia. split rings, with 3/4" dia. bolts at the tower girder connection and 1/2" dia. bolts at the header joist connection.

5. Header joists for catwalk shall be connected to built-up cab beams with two angle plates, L 3 1/2 x 3 1/2 x 1/4 by 8" long, with two 2 5/8" shear plates per face using 3/4" bolts. The 6" face of the angle plate shall be placed against the built-up cab beam.

6. Catwalk decking shall be 2"x 6" S4S Douglas Fir-Larch No. 2 or better.

7. All 2"x 4" handrails shall be connected to each post and diagonal brace with 3/8" dia. lag screws.

8. Handrail post to header joist connections shall be made with two 2 1/2" dia. split rings and 1/2" dia. bolts. At corners, where header joists meet, handrail posts shall be connected at both faces to each header joist.

9. Handrail diagonal braces shall be connected to header joists with two 2 1/2" dia. split rings with 1/2" dia. bolts and to posts at all intersections with two exterior 2 5/8" shear plates at each connection using 3/4" bolts.

10. Top rail board shall be untreated, rough sanded, and finished safe for skin contact.

11. Diagonal braces shall be cut out at bottom where in contact with the header joist the difference between thickness of header joist and rails, to facilitate flush contact with rails along extent.

12. Contractor is responsible to verify all dimensions. Dimensions provided are based on the best information available, but may not be entirely accurate.NOTE: Field verify all existing dimensions and notify

Engineer of any discrepancies immediately.

N.T.S.

CATWALK FRAMING DETAILS

41 FT TYPE TT-1 LOOKOUT TOWER

Technical Services Staff Officer Approved:

Date:

SHEET 2 Of 5

DRAWING NO.

CATWALK DECKING, PLAN VIEW

2"X 6" Decking, typ. all around

Trapdoor, 1 1/2" Marine plywood

2"x 8" or wider decking, as necessary for bearing, typ. both ends of catwalk

3/8" Turned Eye Bolt

4 1/2" Heavy weight ball bearing full mortise swing clear hinge, steel, plated or galv. finish, typ. 3 places

4" flanged pull handle

NOTE: Field verify all existing dimensions and notify Engineer of and discrepancies immediately.

N.T.S.

41 FT TYPE TT-1 LOOKOUT TOWER

Technical Services Staff Officer

CATWALK FRAMING DETAILS

Approved:

Date: DRAWING NO.

SHEET 3 Of 5

CAB BEAM TO HEADER JOIST DETAIL 1

ELEVATION PLAN

TOWER GIRDER TO HEADER JOIST DETAIL

RIGHT ELEVATION PLAN

LEFT ELEVATION

4x4 HANDRAIL POST HEADER JOIST DETAIL

ELEVATION PLAN

N.T.S. N.T.S.

N.T.S. CONNECTION DETAILS

Technical Services Staff Officer

41 FT TYPE TT-1 LOOKOUT TOWER

Date:

Approved:

SHEET 4 Of 5

Project Engr: T. Syverson

4x4 HANDRAIL POST HEADER JOIST DETAIL

ELEVATION

PLAN

L1: L 3 1/2 x 3 1/2 x 1/4 DETAIL

ELEVATION SECTION

L2: L 3 1/2 x 3 1/2 x 1/4 DETAIL

ELEVATION SECTION

L3: L 3 1/2 x 3 1/2 x 1/4 DETAIL

ELEVATION SECTION

N.T.S. N.T.S.

N.T.S.

N.T.S.

CONNECTION DETAILS

Technical Services Staff Officer

41 FT TYPE TT-1 LOOKOUT TOWER

Date:

Approved:

SHEET 5 Of 5

Project Engr: T. Syverson