Appendix 5. - Specifications - IFB PUR1-24-1247 Various Length Timber Ties.pdf

TIMBER TIES IFB PUR1-24-1247

MTA Timber Ties Page 1 of 3

Appendix 5. - Specifications

TIMBER TIES

1.1 DESCRIPTION

A. This Appendix specifies the manufacture, treatment, inspection, and shipment of new timber ties.

1.2 REFERENCE STANDARDS:

A. Timber ties shall be manufactured, designed, handled, treated, delivered, and inspected in accordance with the latest edition of the American Railway

Engineering and Maintenance of Way Association (AREMA) and the

American Wood Preserver’s Association (AWPA) standards, except where these documents are amended by these Specifications.

2.1 GENERAL REQUIREMENTS FOR TIMBER TIES

A. Timber ties shall be new and conform to the requirements of AREMA manual, Volume 1, Chapter 30, except as modified herein.

B. Wood Species – Red or White Oak

C. Sawing – All timber ties shall be straight sawed top, bottom, and sides, cut square at the end, and the bark entirely removed. A tie will not be considered well – sawn where its surfaces are cut into score marks more than ½ inch deep, or where its surfaces are not even.

D. Straightness – A timber tie will be considered straight when a straight line from a point at one end to a corresponding point on the other end is no more than 1-1/2 inches from the surface at all points.

E. Sizing – Timber tie dimensions for each designated size shall not be averaged.

F. Seasoning – All timber ties shall be air dried to an oven dry moisture content of 50 percent or less prior to preservative treatment.

2.2 TIMBER TIES

A. Meet AREMA specifications for timber ties, except as modified herein.

B. Size – 7 inches thick by 9 inches wide.

C. Lengths – 8’ 6”, 10’ 0”, 17’ 0”, 18’ 0”, and 19’ 0”.

2.3 GENERAL QUALITY

A. All timber ties shall be free from any defects that may impair their strength or durability such as decay, large shakes, slanting grain, or large or numerous holes or knots.

MTA Timber Ties Page 2 of 3

1. Decay: Decay is the disintegration of the wood substance due to the action of wood destroying fungi. “Blue stain” is not considered to be decay and is permissible in any wood.

2. Holes: A large hole is one with more than ½ inch diameter and 3 inches deep within, or more than one-fourth the width of the surface on which it appears. Numerous holes are any number equaling a large hole in damaging effect and are not permitted.

3. Knots: A large knot is one having an average diameter more than one-third the width of the rail bearing surface area on which it appears. Numerous knots are any number equaling a large knot in damaging effect and are not permitted. Knots located outside of the rail bearing area of the tie are permitted.

4. Shakes: A shake is a separation along the grain, most of which occurs between the rings of annual growth. The length of a shake cannot exceed one-third of the width of the tie and cannot be closer than one inch to any surface.

5. Split: A split is a separation of the wood extending from one surface to an opposite or adjacent surface. In unseasoned ties, a split no more than 1/8 inch wide and 4 inches long is acceptable. End splits and shrinkage cracks that do not impair the fastening bearing area or strength of the tie will be permitted.

6. Cross Grain: Ties with excessive cross grain are not permitted.

B. Timber members shall be straight grained. Members shall be cut without heart center or sapwood. Small drying cracks or splits are permitted.

2.4 ANTI-SPLITTING DEVICES

A. Nail plates shall be as specified in AREMA Volume 1, Chapter 30, Article

3.1.6 and as specified herein.

B. Nail plates shall be at least 18-gauge galvanized steel conforming to ASTM

A446 Grade 4, and the galvanizing conforming to ASTM A525.

C. Nail plates for timber ties shall be 5 to 7 inches deep by 6 to 8 inches wide.

2.5 PRESERVATION TREATMENT

A. All timber ties shall be pressure treated by the empty cell process with a

60/40 creosote/coal tar solution (Grade C) in accordance with AREMA

“Specifications for Preservatives and Specifications for Treatment” and

AWPA C-6.

B. The retention of the treatment solution shall be a minimum of 8 pounds per cubic foot.

MTA Timber Ties Page 3 of 3

3.1 ANTI-SPLITTING DEVICES

A. At the start of the seasoning period, nail plates shall be applied to both ends of each tie in accordance with AREMA Volume 1 Chapter 30, “Specifications for Devices to Control the Splitting of Wood Ties”, Paragraph 3.1.7.4 b.

B. Application:

1. Gang nail plates shall be centered, plus or minus ½ inch on the timber ends.

2. Gang nail plates shall be driven flush with the ends of the ties.

3. If an excess of 5 percent of the nails fail to penetrate fully, the plate shall be removed and a new plate shall be installed.

3.2 PRESERVATIVE TREATMENT

A. All timber ties shall have all bark, dirt, saw-grease, mud, and other materials removed from the surface so as not to hinder the penetration of the preservative. Apply the preservative in accordance with AREMA Manual, Volume 1, Chapter 30, Section 3.9, and the American Wood Preserver’s

Association Standards C6, as applicable.

B. Notify the Administration when the treated timber ties are ready for shipment. Each treated timber tie shall be stamped for quality control indicating compliance with these specifications.

3.3 MACHINING

A. All machining of timber ties shall be performed prior to preservative treatment.

B. Boring shall be performed in accordance with AREMA Manual, Volume 1, Chapter 30, Paragraph 3.1.4.3.

C. Ties shall be branded on one end in accordance with AREMA, Chapter 30, Article 3.1.4.5 and shall show the following information:

1. Type of Wood

2. Year of Preservative Treatment

3. Identity of supplier and plant

4. Identity of tie owner (MTA).