Brakes - 26C and D-22 - Revisions to Modification 9904, brake conversion for single level cars - September 14, 2001

Mechanical Liaison Officer's reports by Paul L. DeVerter II

The original Modification 9904, Brake Conversion for Single Level Cars, Compatibility with Express Cars in Train Consists Greater than 30 Cars (26C Conversion) may still be followed. However, it utilizes a reinforced rubber hose to connect between a vent valve and the new 900 cubic inch reservoir. Further, this connection is made from the water drainage port of the original 500 cubic inch selector reservoir. This revision repipes the connection through a “Tee” in the selector 9 line at the top of the 500 cubic inch selector reservoir, and utilizes copper or steel pipe between the vent valve and the new 900 cubic inch reservoir, thus eliminating the rubber hose, and leaving the water drainage port unused, and available.

This revision was discussed with Greg Gagarin, and has now been approved by Amtrak. Please see the new drawing attached as Figure 2 – Piping Arrangement (Revised).      Figure 2A has not been redrawn, but the corresponding changes are obvious. The revision allows copper or steel pipe to be used, which is more permanent than rubber hose, the rupture of which may result in the lose of brakes.. The repiping also leaves the water drainage port available for its intended purpose.

Referring to original Modification 9904, and particularly Paragraph 14, change this sentence “The connection between the existing 500 cu. In. selector volume shall be reinforced hose.” to now read – The connection between the existing 500 cu. In. selector volume shall be reinforced hose, copper pipe, or steel pipe. -- Amend the Bill of Material to change item 7 to 1 Hose, Copper pipe, or Steel Pipe, 3/8 inch ID. Add item 9 to the Bill of Material to be 1 Tee, as appropriate. Insert Figure 2 – Piping Arrangement (Revised) as an alternate. The new drawing is attached. Original Figure 2A should be read is light of this revision.