IFB # 142F-24 Switch Timber Crossties.pdf

MASSACHUSETTS BAY TRANSPORTATION AUTHORITY

SYSTEMWIDE MAINTENANCE AND IMPROVEMENTS

MAINTENANCE OF WAY DIVISION

SPECIFICATIONS

FOR

SWITCH TIMBER CROSSTIES

VARIOUS LENGTHS

JUNE 2018

I. MATERIAL

A. Switch ties shall be Black Locust, Honey Locust, Red oak, White oak or Black Walnut or approved equal.

B. All cross ties shall be in accordance with AREMA Specification for timber switch ties, except where modified herein.

II. DESIGN

A. Crossties shall be Grade 5, 7” x 9” x “Varies” per MBTA Drawing #201S. Please refer to Requisition Order Form for quantity and lengths.

B. The length and thickness specified are minimum dimensions. Ties one inch (1”) wider or thicker or over three inches (3”) longer at any point than the dimensions specified above will be rejected.

III. MANUFACTURE

A. All ties shall be manufactured from sound, live timber and must be free of any defects that may impair their strength or durability as switch timber ties, as further described in this section. Every effort is to be made to get the felled timber to mill and milled timber to treatment facility for seasoning as quickly as possible to avoid wood fiber infection.

B. All ties shall be straight, well sawn on all four (4) sides, but square at the ends, have top and bottom parallel and have bark completely removed. A cross tie will be considered straight when a straight line along the top, from the middle of one end to the middle of the other end, is entirely within the tie, and when a straight line along a side, from the middle of one end to the middle of the other end, is no more than two inches (1 1/2”) from the top and bottom of the tie. The top and bottom will be considered parallel if any difference at the sides or ends does not exceed 1/8”.

D. All timber ties shall be free from the following defects:

1. Decay

Switch timber ties that show decay of any nature and ties that show stain from being left in the log too long will be rejected. “Blue stain” is not considered decay and is permissible in any wood.

2. Holes

Ties will be rejected if a large hole, or numerous holes with the net effect of a large hole, is present. A large hole is one exceeding one-half inch (1/2”) in diameter and three inches (3”) deep outside the sections of the ties between twelve inches (12”) from the end.

3. Knots

Ties will be rejected if a large knot, or numerous knots with the net effect of a large knot, is present. A large knot is a knot whose average diameter is greater than one-fourth (1/4) the width of the surface of which it appears within the area of the tie between twelve inches (12”) from each end.

4. Shakes

Shakes greater than one-third (1/3) the width of the tie shall be cause for rejection of the tie.

5. Splits

A tie will be rejected if a split exceeds five inches (5”) long or one-half inch (1/2”) wide.

6. Slanting grain

A tie will be rejected if a slant in grain in excess of one (1) in fifteen (15) is present, except in the case of woods with interlocking grain.

6. Wane - Excessive wane will be cause for rejection of the tie. A maximum of 1” wane will be allowed in the rail bearing area of the tie.

IV. SEASONING

A. Crossties will be air seasoned prior to treatment. Ties shall be stacked for seasoning in accordance with AREMA Specifications, Chapter 3, Part 5, Section 6. Seasoning shall continue for at least twelve (12) months and no more than eighteen (18) months.

B. In the absence of air-seasoned crossties, the Vapor or Boulton drying process may be used with the permission of the Division Engineer or his designee.

C. Sufficient borer cores shall be taken of seasoned ties to determine that adequate drying has taken place so that ties may be satisfactorily penetrated with preservatives.

D. Prior to seasoning, all switch timber ties shall have nail plate anti-splitting devices applied at each end of the tie. Nail plates shall be Gang-nail, as manufactured by Portec, or approved equivalent, and shall be of at least 18 gauge galvanized steel conforming to ASTM A446, Grade4, and the galvanizing conforming to ASTM A525. Dimensions shall be as recommended by manufacturer. One nail plate shall be positioned onto each end of the tie with the plate placed to cover the greatest area of splitting. Nail plates shall be applied by a mechanical device capable of squeezing the splits together bringing the tie back to its original dimensions prior to application.

V. TREATMENT

A. Switch timber tie treatment shall be retention of seven (7) pounds per cubic foot or refusal using the empty cell process in accordance with the latest standards of AREMA Specifications, Chapter 30, part 3 paragraph 3.7. The standard for the creosote solution is as per AWPA specification P2-06.

B. Sufficient number of borings shall be taken after treatment to determine proper penetration.

VI. INSPECTION

A. Supplier shall retain the services of an independent inspection company who shall inspect all ties before, during and after treatment. Inspection of ties shall be in strict accordance with the American Wood Preservers Association (AWPA) Standard M-2.

Copies of inspection reports shall be sent to:

Director Maintenance of Way -Building 2

21 Arlington Ave.

Charlestown, MA 02129

B. Any ties found by the inspector to not meet this specification shall be rejected and not delivered to the MBTA.

VII. DELIVERY

A. To be accepted, all switch timber ties shall conform to this specification in all respects and are at the supplier’s risk until accepted at the delivery site. Ties that are rejected for non-compliance with this specification will be returned at the supplier’s expense.

B. Ties to be banded with 2” heavy duty steel bands to prevent the ties from shifting while in shipment or being handled upon receipt. No one bundle to exceed 5000 lbs.

C. Ties shall be delivered via motor freight (road) only to the MBTA Charlestown Rail shop, 21 Arlington Ave, Charlestown, Massachusetts 02129.

D. Notification of delivery is to be made two (2) business days in advance to the

Supervisor of Yard Services, (617) 222-5290. All materials are to be shipped during the hours 7 AM to 1:30 PM Monday through Friday.

M.O.W.

DIVISION

ANTI-SPLITTING END PLATE FOR

WOODEN CROSS-TIES

9"

7"

Varies s

34"

9"

R

E F

HEADBLOCK TIE, DAPPED 34" LONG BY 2" DEEP

9" X 9 ’-0"

TREATED HARDWOOD

NOTES:

1. TIE TO ADHERE TO MBTA TIE SPECIFICATION 9263.

2. DAP DESIGNED IN REFERENCE TO SWITCH MACHINE

CENTERLINE LOCATED 42" FROM NEAR MAINLINE GAUGE LINE.

13'-0"

13'-0"

10'-2"

13'-0"