420 Lexington Avenue Joseph Giulietti New York , NY 1001 7-3739 President www.mta.info e Metro-North Railroad November 18, 2016

Gary G. Fairbanks Staff Director, Motive Power and Equipment Division U.S. Department ofTransportation, Federal Railroad Administration Office of Safety Assurance & Compliance 1200 New Jersey Avenue, SE Washington, DC 20590

Re: MTA Metro-North Railroad M8-S Passenger Cars, Docket Number FRA 2004-17099

Subject: Petition for Metro-North Railroad's M8 Passenger S-Car Air Brake Maintenance under 49 CFR 238.309(d)(3)

Dear Mr. Fairbanks;

This letter is in response to the FRA letter of same reference, dated October 07, 2016 to Metro-North Railroad (MNR) for clarification ofM8-S Passenger Cars.

The MNR fleet ofM8 Passenger cars consist of380 multiple units (MU's) of A & B cars and 25 Single Cars. The entire 405 car M8 Fleet is equipped with the Knorr Brake Electronically Controlled Pneumatic Air Brake System for MU service on MNR' s .

MNR recognizes the FRA's concerns with slight differences in operation of the air brake system on the S-car which used in MU service and what role it might play in the Periodic brake equipment maintenance on the M8 Single Passenger Cars. MNR is requesting the possibility of the 25 M8 Single (M8-S) Passenger Cars to enter into an Age Exploration program comparable to both the & M8 MU Fleets to fully determine the safe allowable brake maintenance interval.

The 25 M8-S passenger cars are equipped with the Knorr Brake KB-CTl a Air Brake System. This system is a micro-processor controlled electro-pneumatic air brake system, with extensive real-time monitoring and a mechanical pneumatic back-up system, designed to specially operate with M8 A & B MU cars. The brake system on the M8 Single Cars has only minor differences with its M7 & M8 MU counterparts. These differences include no dynamic brake function and no Tread Brake Unit (TBU) only In-shot braking, which was used for wheel cleaning purposes. M8-S car does have many items in common with the M7 & M8 MU 's; it utilizes P-wire for brake rate control, uses only existing tested valves, foundation equipment, shares the same high quality air from the MU's ASU, and has micro-processor control with real-time feedback to the operator if any ofthe braking control is out of tolerance. Also M8-S cars are equipped with , 3'd rail Shoe Mechanism, auxiliary (hotel) power and electric coupler.

MNR' s would like to utilize the same test plan as the M7 ' s to properly document the operation and maintenance of the unique M8 S-car for MU service. The testing will be conducted on a calendar year basis using 2 M8-S vehicles per year, starting at 3 years of revenue service. The test specifications utilized for the test will consist of the same standards as already approved by the COT&S Air Brake committee from the KB-CTl and KB-CTia systems. MTA Metro-North Railroad is an agency of the Metropolitan Transportation Authority, State of New York Thomas F. Prendergast, MTA Chairman and Chief Executive Officer Should you have any question please don't hesitate to contact the undersigned.

Enclosures Reg:rts, A- {~ ~

Seyed A. Hosseini Director, Equipment Engineering Maintenance of Equipment MT A Metro-North Railroad I 00 Croton Yard Croton-On-Hudson, NY I 0520

Telephone: 914-271-1737

MTA Metro-North Railroad is an agency of the Metropolitan Transportation Authority, State of New York Thomas F. Prendergast, MTA Chairman and Chief Executive Officer 8 Metro-North Railroad

M8 S-Car Brake System Overview

The M8 S-car Air Brake System utilizes a microprocessor controlled Friction Brake Unit, it's designed to interface with various control signals from the vehicle and propulsion system. The electronic control system includes the capability to perform closed loop feedback control of the pneumatic friction brake BC pressure based on demanded braking effort, LW, and Wheel Slide control.

The M8 S-car air brake system is a friction only air brake system receiving its commanded brake effort via P-wire control and offering a pneumatic back-up control for EB braking. The Friction Brake effort on an S-car is provided by 8 cheek mounted disc/caliper brake units (DBU) and 8 tread brake units (TBU), all of which are air applied and spring released. 4 of the DBU 's include a spring applied park brake feature for securing the equipment.

This system has been designed to have the thermal capacity to safely stop the S-car using friction only braking from MAS during normal MNR train service.

The S-car uses the clean dry compressed air from the ASU from the M8 B­ ears and operates at the same 130-150 psi brake pipe pressure.

The air brake system design of S-car is very similar to the M8 A & B cars. The system uses the same prove air brake components as the M7 & M8 cars and will also see the same braking duty cycle as the M8 MU's. The main difference within the application is the pressures being applied to the cylinders during the dynamic stops; the S-car will be at a Full Service Brake (FSB) pressure of approximately 30 psi where an A & B car will be at a much lower in-shot pressure of 5 to 7 psi until blended braking has completed at which time a FSB pressure of 37 psi.

As described above the M8 air brake system design for A, B, and S cars share many of the same operating characteristics.

The End

M of E Equipment Engineering November 8, 2016