Standardized Technical Specification

PRIIA 305 Next-Generation Equipment Committee Bi-Level Passenger Rail

Chapter 5

Trucks

Table of Contents 5-1

Table of Contents

5.0 Trucks ...... 5-2 5.1 Overview ...... 5-2 5.2 General Requirements ...... 5-2 5.3 Ride Quality and Performance ...... 5-3 5.4 Truck Design ...... 5-3 5.4.1 Truck Frame and Bolster ...... 5-3 5.4.2 Bolster Anchor ...... 5-4 5.4.3 Suspension ...... 5-4 5.4.4 Stops ...... 5-5 5.4.5 Hand Linkage ...... 5-5 5.4.6 Adjustments ...... 5-6 5.5 and Assembly ...... 5-6 5.5.1 ...... 5-6 5.5.2 ...... 5-6 5.5.3 Brake Discs ...... 5-6 5.5.4 Journal Bearings ...... 5-6 5.5.5 Journal Bearing Housings ...... 5-6 5.6 Shock Absorbers and Shock Mounts ...... 5-7 5.7 Electrical Wiring ...... 5-7 5.7.1 Speed Sensor ...... 5-7 5.7.2 Grounding ...... 5-7 5.8 Painting ...... 5-7

Trucks 5-2

5.0 Trucks

5.1 Overview

Each shall be equipped with two four-wheel trucks. Trucks shall be designed for operation at all speeds up to 125 mph. Truck frames may be either cast or fabricated. The trucks shall incorporate braking via tread and disc . Truck design shall be proven for safe and reliable operation on all FRA Classes of track up to and including Class 7.

5.2 General Requirements

The truck assembly shall be a four wheel, roller bearing truck designed for operations specified in Chapter 1 (Track Geometry). A comfortable ride shall be provided at all permissible speeds under normal operating conditions. Truck designs must have a proven service history in North American intercity or commuter rail service, or must be demonstrated as being compliant with all Specification requirements through finite element analysis, truck dynamic behavior through computer simulation (validated as defined by the Customer) and instrumented testing at an approved test track facility. The truck dynamic characteristics shall be suitable for a bi-level car and must demonstrate appropriate response for all speeds, curves, spirals, switches and turnouts, and for all typical track perturbations found within defined safety limits of FRA track geometry standards and as described in this Specification. The truck design must meet this level of suitable performance for up to 5 inches of cant deficiency.

Truck wheelbase shall be 8 ft 6 in. Truck centers shall be spaced 59 ft 6 in. apart, equal distance from the car’s lateral center line. Trucks shall be designed to operate under the environmental and operating conditions identified in PRIIA Specification 305-912, including track configurations. All truck-mounted equipment shall conform to the clearance requirements of PRIIA Bi-level Clearance Drawing PRIIA 305-801. Trucks shall be interchangeable from one end of the car to the other, and all trucks and bolsters shall be directly interchangeable between all car types addressed in this Specification.

The truck shall be equipped with the brake equipment specified in Chapter 7. The arrangement shall be inboard mounted. Brake equipment shall provide braking rates as identified in Chapter 7.

The truck shall be locked to the carbody with a safety mechanism consistent with 49CFR Part 238 requirements.

Provisions shall be made for use of a wheel truing machine, for reprofiling wheels while mounted on a car; without requiring any degree of truck disassembly. Access to the ends of the axle, for wheel truing, shall be available without the removal of any additional parts, including roller bearing end caps (with the exception of cover plates, plugs or axle tachometer generators.)

All truck assembly parts shall be designed to withstand maximum stresses as called out in APTA Recommended Practice RP-M-009-98. See Chapter 19 for stress analysis requirements.

Trucks 5-3 Truck components shall be designed to have sufficient clearance but no less than 1.0 in. to prevent unintended contact of truck-to-truck or truck-to-carbody components under all loading and track conditions including worn wheels and failed springs.

5.3 Ride Quality and Performance

Ride quality for all proposed truck designs shall be demonstrated analytically and through actual track testing (at an approved test facility) per the requirements of Chapter 19. Truck designs with proven service history on North American intercity or commuter railroads may be validated analytically, if the validation methodology is approved by the Customer. Some or all portions of the required design validation tests may be waived at the sole discretion of the Customer if design adequacy can be proven by submittal of existing engineering analysis and demonstration of successful service history of the truck design.

A comfortable ride shall be provided at all permissible operating speeds for each FRA track class, up to the vehicle rated speed. A comfortable ride is defined as weighted root mean square (rms) acceleration less than 0.032g and a crest factor less than 9. Weighted rms acceleration and crest factors shall be calculated according to ISO 2631.

5.4 Truck Design

5.4.1 Truck Frame and Bolster

Truck frame and truck bolster shall be of cast or fabricated steel construction. They shall be heat stress-relieved after all primary welding is completed. Critical areas of all welds and castings shall be magnetic-particle inspected per ASTM E709-01, radio-graphically inspected per ASTM E94-04 or ultrasonically inspected per AWS D.1.1.

Rotational range of motion shall be limited by stop blocks with replaceable wear surfaces mounted to the center sill. The truck shall not contact any other part of the carbody or suspension throughout its range of motion.

All wearing parts or surfaces shall be provided with renewable liners or bushings. Truck frame pedestals, if used, shall be lined with low-friction polycarbonate components to minimize wear. Truck design shall permit replacement of pedestal liners without requiring the removal of the wheelset.

This truck design shall provide sufficient restraints to prevent hunting of the truck at all speeds up to 125 mph, with worn wheels and other components at their condemning wear limits, in accordance with 49CFR Section 213.333, 49CFR Section 238.227 and APTA Recommended Practice RP-M-009-98.

The design of the trucks shall be analyzed and validated in conformance with the requirements stated in Chapter 19, to verify that the truck design meets all safety, ride quality, durability and maintainability requirements.

A centering bearing or pivot shall be located between the truck bolster and the truck frame at its center.

Trucks 5-4

5.4.2 Bolster Anchor

Longitudinal forces shall be transmitted between the truck and the carbody through bolster anchors. The bolster anchors shall be designed to accommodate longitudinal, swiveling and vertical forces encountered during operation on all classes and conditions of track identified in PRIIA Specification 305-912. See Chapter 4 for other requirements for the bolster anchor and related mounting points.

5.4.3 Suspension

Primary and secondary suspension arrangements must be of proven arrangement for application on a bi-level car.

Primary suspension shall be designed for a minimum functional service life of eight years. Deflections in primary suspension due to asymmetric forces from tread brakes shall not result in an unacceptable level of influence on wheelset angle of attack. The car body secondary suspension shall be provided by coil springs located at each end of the bolster.

At the Customer’s request, air springs or other alternative secondary suspension arrangements may be proposed in lieu of steel coil springs. Alternative arrangements must meet all criteria set for this Specification for acceptance. Lateral and vertical motion of the bolster shall be damped by hydraulic shock absorbers and/or air orifices (if is used). Longitudinal and swiveling motion of the bolster shall be prevented by bolster anchors between the carbody and bolster.

Vertical P2 forces shall not exceed 68,000 lbs with a 1° dip angle using the Esveld equation.

Esveld Equation:

Trucks 5-5

The parameters in the P2 force calculation are:

P0 is the nominal static vertical wheel load (pounds)

2α is the total dip angle at a joint, weld dip or other rail discontinuity (radians) v is the speed (inches/sec) 2 mu is the of the wheelset (pounds-sec /inch) 2 mT2 is the equivalent track mass (pounds-sec /inch)

CT is the equivalent track damping (pounds-sec/inch)

KT2 is the vertical track stiffness (pounds/inch)

The assumed values of selected parameters are: 2α = 0.017 rad, (1 degree) with half of this (α) on either side of the dip. 2 mT2 = 1.1335 pounds-sec /inch, for nominally stiff concrete tie track

CT = 671 pounds-sec/inch, from literature for nominal track conditions

KT2 = 330,000 pounds/inch, for nominally stiff concrete tie track which corresponds to a track modulus of 4000 pounds/in/in (assuming a track deflection of 0.10 inches under a wheel load of 33,000 pounds)

A safe ride shall be provided in the event of a broken spring, inoperative damper or collapsed or over-inflated air spring (if used).

A minimum of 0.75 in. of vertical free travel shall be provided for the range of normal load conditions. Free travel is defined as the change in vertical displacement between the axle center and a carbody reference point as measured under static load conditions with an empty car (AWO) and a fully loaded car (AW3). Sound and vibration deadening inserts shall be provided for all spring seats.

Springs and chevrons, if used, shall be designed for ease of replacement and maintenance Chevrons shall be secured to the truck frame when axle assemblies are removed. Chevrons shall be color-coded for spring rate and shall be installed in matching pairs on each axle assembly of the truck.

Coil springs, if used, shall be thoroughly shot-peened after grinding and then coated in accordance with a Customer-approved paint type.

Unless otherwise noted, all coil springs shall meet the latest revision of AAR Standard M-114.

5.4.4 Stops

Rubber stops limiting vertical and lateral motion shall be designed with a progressive compression rate and shall not exceed 90% of their design compression under any condition that can be developed in the truck. Lateral stops shall limit the motion of the car body to 1.5 in. in either direction. Stops that limit truck over-rotation shall be equipped with a replaceable liner to prevent metal-to-metal contact.

5.4.5 Hand Brake Linkage

Truck-mounted hand brake linkage shall be provided on the B-end truck per the hand brake requirements contained in Chapter 7. All trucks shall be equipped with necessary attachment points for hand brake linkage as specified in Chapter 7.

Trucks 5-6 5.4.6 Adjustments

Provisions shall be made for adjusting the carbody height up to 0.75 in. in either direction from nominal (1.5 in. total adjustment range), in increments of 0.25 in., to compensate for wheel wear or other variations. Suspension design shall permit adjustments to be made without disconnecting the truck from the carbody. Air spring leveling valve adjustment shall not be used for adjusting carbody height.

5.5 Wheel and Axle Assembly

The wheel and axle assembly shall consist of an axle, two wheels, two outboard journal bearings, two inboard brake discs, 104-tooth speed sensor gear at each journal and associated materials. This wheel and axle assembly shall be fully interchangeable in form, fit and function with Amtrak standard wheel assembly for bi-level cars. Mounting graphs and inspection records shall be included in each vehicle history book for all components.

5.5.1 Axles

The axle shall be of solid, forged, Grade "F", carbon steel furnished to AAR Standard M-101. It shall have dimensions as specified for a Class F axle according to APTA Recommended Practice RP-M-001-98 and PRIIA Drawing 305--805 for a four wheel (per truck) configuration.

5.5.2 Wheels

The wheels shall be 36 in. diameter (nominal) Class B, multiple-wear type, conforming to AAR Standard M-107-84 and APTA Standard SS-M-012-99, and shall have a 1 in 40 tapered tread.

5.5.3 Brake Discs

Brake discs shall be of self-ventilated "mono-block" construction, 28 in. diameter as specified in Chapter 7.

5.5.4 Journal Bearings

The journal bearings shall be fully enclosed, grease lubricated, Timken Type "G" roller bearings configured for No Field Lubrication (NFL), AAR Class "G" 6.5 in. by 12 in., with HDL seals (or equivalent). The service life of the journal bearing shall be at least 1 million miles under AW3 loading.

5.5.5 Journal Bearing Housings

Removable journal bearing housings (journal boxes) shall be provided. Pressing shall not be required to remove the journal box from the bearing. Journal boxes shall be common for all locations, or may be common for all right-hand sides and left-hand sides, respectively.

Each journal box shall be drilled and tapped in four locations, two locations to the left and two to the right of top-dead-center, to accommodate up to two speed sensors, and a hot bearing detector, per PRIIA Drawing 305-804.

Trucks 5-7 5.6 Shock Absorbers and Shock Mounts

Lateral and vertical motion of the trucks and suspension shall be damped through the use of shock absorbers and/or air orifices (if air suspension is used). Shock absorbers, if used, shall be of a hydraulic type terminating in elastomeric bushed connections to eliminate metal to metal contact. All shock absorbers shall be accessible for replacement without requiring the removal of the trucks from the carbody.

Shock mounting brackets on the trucks and carbody shall be designed to last the life of the carbody without wearing, deforming, loosening or otherwise requiring repair.

Durability of the shock absorbers, shock mounting brackets and bushings shall be demonstrated analytically and through accelerated life cycle testing simulating actual functional service life. Test plan for the shock absorbers and shock mounts shall be submitted to the Customer for approval as part of the Contractor’s proof of design testing (see Chapter 19).

The shock absorbers shall be appropriately rated for a service life of no less than five years.

5.7 Electrical Wiring

5.7.1 Speed Sensor

A speed sensor cable shall be provided on each truck to provide a signal from the 104-tooth gear located on each axle to the wheelslip control system (see Chapter 7). The speed sensor cables shall be attached to the truck frame using coated steel clamps that provide secure attachment while not abrading or pinching the cable. Each clamp shall secure no more than one cable. Clamps shall be securely fastened to the truck frame. Appropriate slack shall be incorporated into the cable length to allow free movement of trucks and truck components while providing adequate securement for the cable. Cables shall be routed to prevent damage from pinching, stretching or catching on adjacent equipment.

5.7.2 Grounding

An electrical ground path using highly flexible cables or straps shall be provided from each journal bearing to the car body. Grounding paths shall be run from each journal box to the truck frame, from the truck frame to the truck bolster and from the truck bolster to the car body. Grounding cables or straps shall not restrict the movement of truck components, and shall remain slack under all operating conditions.

5.8 Painting

The truck manufacturer shall apply at least one coat of a metal primer on all exposed surfaces of the trucks immediately after final assembly cleaning, repairs, and inspection.

Final coat of paint will be applied in accordance with exterior graphics requirements in Chapter 23.

* End of Chapter 5 *