Train Inspection Flashcards
“two pack” configuration
Wagons where 2 hoppers are connected in the middle by a solid drawbar
Benefits of Two pack configuration
saves on weight and additional braking gear by sharing the braking of both wagons through one triple valve and associated equipment
“Monocoque” configuration
wagons where the structural strength of the wagon is maintained by the overall wagon shape and unlike conventional wagons they do not have a solid underframe to support the wagon
Conventional Wagon
Consisting of a central load bearing frame, or two side frames, and a sill at each end.
The sill carries
a coupler and draft gear by which vehicles are couples together to form a train
Irrespective of the type of vehicle, items such as the following are fixed to the vehicle frame or body
Access ladders, steps, handrails, handbrakes, platforms
Bogies
The assemblies which carry the 4 wheels and 2 axles, which pivots beneath each end of the vehicle and on which the vehicle is carried
Three-piece bogies
consist of a central bolster, on which the from of the vehicle sits, and which separate and support the two side frames
Bolter
Rides on the springs in the side frame, providing the vehicle with its suspension
The side frames
ride on and separate the wheel and axle sets and maintains the geometry of the bogie
Underframe
the load-bearing structure that carries the majority of the weight, and draft forces on the vehicle
The underframe consists of
either a central spine or two side frames
Benefits of Monocoque construction
all of the draft forces and all of the weight of the vehicle is carried by the external skin. Often used on passenger cars to reduce weight and cost
End sill
the cross member that forms the ends of each vehicle. In conventional vehicles, there are two (one at each end)
The end sill carries important equipment, including
couplers, end steps, handrails, ladders, handbrakes, end cocks and air hoses
Draft gear
designed to absorb the draft and buff forces inflicted on the vehicle and transmit these forces to the vehicle, enabling it to be moved
Draft forces
Those which are inflicted to haul the vehicle in the direction of the leading coupler. Commonly known as lifting or stretching of the train.
Buff Forces
those that are inflicted to push the vehicle away from the knuckle at which the force is inflicted. These are referred to as “running in or bunching of the train”
Conventional Draft Gear Consists of
a draft pocket, a draft package, a draft yoke, a coupler assembly
Draft pocket
a reinforced fabricated box, within, and at the ends of the central frame into which the rest of the draft gear is installed
Draft package
absorbs many of the shocks inflicted on the vehicle, and usually consists of an assembly of rubber pads bonded to steel plates arranged like a multi-layered sandwich. Providing a certain amount of give to absorb most longitudinal shocks
Brackets in the draft pocket
restrain the ends of the draft package, fore and aft.
How are draft forces transmitted to the vehicle to move it?
as forces are transmitted to the draft package, it is forced forward/backwards but is unable to move due to the restraint provided by the brackets
Draft yoke
a cast steel loop that surrounds the draft package and transfers draft and buff forces from the couplet to the draft package. At the front, a large hardened steel pin allows the couplet to pivot from side to side
The coupler assembly consists of
the automatic coupler, its knuckle and pin, and knuckle locking mechanism, cast integral with a coupler shaft. Through the end of the coupler shaft, a large hardened pin links the coupler shaft with the draft yoke
Automatic couplers
devices fitted to both ends of all locomotives and vehicles so they can be coupled together
The “B” end of a vehicle is to be determined as follows
On two-packs, the hopper with the triple valve braking equipment on the inside end sill is designated the “B” end. The end with the Triple valve attached
Automatic Brake system
the Westinghouse system of air brake which one air pressure works against or in concert with another than will automatically apply if the pressure of compressed air in the controlling pipe is reduced by any cause
Auxillary Reservoir
a reservoir on each vehicle that contains a supply volume of compressed air, which is the source of air pressure used to fill the air brake cylinder and apply the brakes
The three functions the triple valve performs
CAR. Charges the brake pipe, Applies the brake, Releases the brake and causes the system to be recharged in readiness for another application
Brake pipe
connects the locomotive air brake equipment through the length of the train via flexible air brake hoses
A brake application is initiated by
making a reduction in brake pipe air pressure. The triple valve on each vehicle, which causes air to flow to the brake cylinders, detects this. The brake pistons in each brake cylinder act on rigging, and forces the brake blocks onto the wheels
The braking force produced is proportional to
the amount of the brake pipe pressure reduction made by the locomotive driver
The brakes are released by
admitting air from the loco’s main reservoir into the brake pipe. This is detected by the triple valve on each vehicle, which then causes air to discharge from the brake cylinders and release the brakes
At the same time the brakes are released
the auxiliary reservoirs are recharged with air from the brake pipe
A rupture of the brake pipe due to train parting or other incidents causes
an escape of air pressure from the brake pipe resulting in an immediate application of the brakes throughout the train
Even the simplest of air braked vehicles carry the following equipment
A brake pipe, end cocks, a branch pipe isolating Cock, a triple valve, an auxiliary reservoir, a release valve, a brake cylinder
Other air brake refinements that can be found
equipment to compensate for light/heavy loads, equipment to help maintain braking control of long downgrades, equipment to hasten the application and release of the brake
The charge position for brake operation
When the triple valve responds to an increase in brake pipe pressure by connecting the brake cylinder to brake exhaust and the brake pipe to the Auxiliary reservoir
The application position for brake operation
The triple valve has responded to a decrease in Brake pipe pressure by connecting the Auxiliary reservoir to the brake cylinder. The brake exhaust and the brake pipe to the auxiliary reservoir are closed off
The Release Position for Brake operation
the brake pipe has been recharged to 500kPa. The triple valve has responded to the increase in brake pipe pressure by connecting the brake cylinder to brake exhaust, and the brake pipe to the auxiliary reservoir
Load Compensating equipment
Equipment provided to better match the available braking effort to the mass of the vehicle. As the mass is increased, the available brake cylinder pressure, and thus braking power, is increased
Benefits of load compensating equipment
Allows the brake cylinder pressure to be maintained at a lower level when the wagon is empty, that provides sufficient braking power for the empty vehicle without the danger of the wheels being locked up under brakes
Brake Cylinders
can be found in different positions but they are all used to apply the brakes
When the brake piston is extended
it applies the brake by applying the brake block onto the wheel
The basic components of most handbrakes
Wheel, chain, ratchet, release lever, locking pawl, Housing
Process to apply handbrake
Wind in required direction, ensure locking mechanism engages, ensure chain does not snag or foul, check piston has been applied, check blocks are applied to the wheels, apply with air before using handbrake whenever possible
Process to release handbrake
lift release lever, ensure body is away from moving parts, On occasion AAR types may require winding a 1/4 turn in the opposite direction to release tension before operating release lever, check chain is fully released and not snagged (smiley face), check piston has retracted, ensure brake blocks are released off the wheels
In regards to handbrakes it is your responsibility to)
Ensure handbrakes are released prior to departure, utilise handbrakes if stabling wagons or conducting repairs
Conventional Three-piece type Bogie
consist of two side frames (holding the springs and axles) and a cross member or bolster to which a centre casting and side bearers is fitted
Friction wedges
control the vertical motion of the bolster in the side frames and act as a dampener to control the ride of the bogie by exerting sideways pressure between the bolster and the wear plates of the side frame opening in which the bolster can move vertically
Purpose of a nest of coil springs in the side frames
provided to support the bolster in the side frames
Inspection of springs should be made to ensure
that no coils are missing, displaced or broken. That coils aren’t touching with at lease 2mm clearance between coils
How many springs can be broken on a wagon
only 1 can be broken or misplaced, but only under exceptional circumstances, and should never be allowed to leave a service facility in this condition
The maximum allowable wear to friction wedges
A combined weight of 46-50mm protruding above the gib before green carding, if above 50mm the wagon must be red carded and removed from the train
Brake gear support
The brake beams are supported by the side frames and are fitted into a slot (guide) or by means of a bracket and hanger. Either method allows for free movement of the brake beams
Major contributing factor to improved performance of roller bearings
the ability of wagon inspectors and repair personnel to recognise damaged roller bearings and worn/damaged associated parts
Common problem with “box” type axle bearings
the threaded plug on the front may dislodge, allowing for the possibility of contamination of the bearing.
If a plug is found missing from a “box” type bearing
it must be red carded for the attention of maintenance personnel
Package type bearing must be checked for
the presences of excessive loss of grease
A bearing which is found to have a large quantity of grease on the outside of the bearing should
be green carded for inspection by maintenance personnel
How to test bearing temperature
place back of a bear hand on the bottom of the bearing. If it cannot be kept there for more than a few seconds, it is running hot and should be red carded for inspection. May also smell like burnt grease
Visually detectable defects inspection for bearings should include
check the axle end cap for missing lubricant fittings/plugs, check for loose and/or missing cap screws, ensure that all tabs for the locking plate are properly bent up against the flats of the cap screw heads, inspect for damage or wear to the end cap from a displaced (cocked) adapter
Constant contact side bearers
pre-loaded to provide a designed amount of loading between the bogie and frame to provide superior bogie stability
The maximum permissible speed of vehicles provided with constant contact side bearers
may be as high as 110km/h
How does an automatic coupler work?
The coupler uses a pivoting knuckle and an internal locking mechanism that automatically locks when the knuckle is pushed closed
Coupler knuckles are designed to
take huge buff and draft forces, but are generally the weakest point in a wagons design and can be broken by poor train handling, careful inspection of the wear limits must be made to ensure that the train’s integrity is maintained
Coupler head
houses the Auto lifter and locking block assembly and holds the knuckle
Shank
Fits into the Yoke, joining the coupler head to the yoke. It is held in place by a pivot pin or key
Tooth
guides the automatic couplers together when coupling
Locking block
Moves up to allow the knuckling to open, move down to lock the knuckle
Knuckle
Opens and Closes to allow coupling and uncoupling of vehicles
Knuckle Pin
Allows the knuckle to pivot so it can open and close, also holds the knuckle in place when it is opened
Auto Lift Pin
attaches the uncoupling rod to the locking block and releases the knuckle when the lever is operated. This may be mounted on either the top or bottom of the coupler
Describe the Knuckle Service limits
A condemnation indicator is located on the top surface of the coupler knuckle. If the draft and buff surfaces of the knuckle are worn to such extent that the condemnation indicator is reached, the knuckle has reached the end of its service life and must be replaced
What must be paid attention to with couplet knuckle pins?
They must protude from the bottom of the coupler head. Any broken knuckle pins must be replaced
Wagons fitted with rotary type couplers, MUST have the split pin in place to ensure
that the knuckle pin does not fall out when the wagon is inverted during unloading at a rotary tippler
Components of a coupler knuckle
knuckle pin, centre line, locking block, lift pin, hole for knuckle pin, limiting lug
Procedure to replace a coupler knuckle
Confirm/establish 3 step protection, ensure the coupler locking block is in the raised position, while firmly supporting the knuckle roll the knuckle into the coupler head inclining it slightly upwards to clear the limiting lug in a clockwise arc, replace the knuckle pin, replace the knuckle pin safety split pin (and spring where fitted)
Procedure for replacing air hoses
Obtain a replacement hose of the correct thread size, seek and establish end ECP protection, ensure end cocks are closed, uncouple air hoses, using correctly set Stillson loosen the hose in an anti-clockwise direction, remove the hose by hand when able, insert a replacement hose into the end cock fitting, tighten as far as possible by hand, using stilsons tighten only as far as necessary to align the coupling head for ease of coupling
Describe brake block limits
measured on the outside facing surface at the thinnest end in line with the toe (end) of the brake head. Condemning thickness is generally 12.5mm for composition blocks
Procedure for changing brake blocks
Observe all applicable safety rules and regulations, wear appropriate personal protective equipment
Procedure for removing brake blocks
Obtain end ECP protection if wagon is attached to a locomotive, disconnect air from wagon and bleed air from reservoir, disconnect ECP cable, Drain air from system using air release lever, select correct tools, using chisel bar lever brake block away from wheel, remove brake block spear using chisel bar, remove brake block by hand and discard
Procedure to replace brake blocks
select correct brake block for wagon, place brake block in correct position on brake head with number facing out, fit brake block spear through brake head making sure it passes through eye on brake block, tap brake block spear using hammer to make sure it is secure, do not tap brake block spear too hard
Describe modern wheels
disc types with integral tyres, tyre and wheel are made as one unit
The wheel centre comprises of
the rim, spokes or disc, boss and wheel seat through which the axle is fitted
A wheel set consist of
an axle and two rigidly pressed on wheels.
List possible wheel defects
Skidded (flat spotted), Scaled (build up on wheels), Spalled (Flaking from tread), Cracked (thermal or fatigue), hollowed (sever wearing to profile
Describe Skidded wheels
result from the wheel being locked up in motion, and sliding along the rail head, wearing the wheel tread flat at that point
Severely skidded wheels can cause
rail breakage, axle bearing failure and possibly derailment
Skidded wheels are condemned when
the single skidded flat spot is in excess of 60mm in length, or two successive or adjoining flat spots of 40 to 60mm are together on the wheel tread
Condemned skidded wheels are
not to travel, and need to be RED carded for attention. Grade 4 skids green card to destination and red card on arrival
Skidded wheels are most often the result of
handbrakes that have not been released, or air brakes that have failed to release, due to mismanagement of the air brake
Describe Scaled wheels
a build up of metallic material on the tread of the wheel
Scale build up is usually a result of
sticking brakes which cause the wheel to slip on the track and heat the wheel to the point where the metal becomes molten and flows on the wheel tread surface. While molten, the metal mixes with brake dust and dirt then deposited back onto the tread, cooling in layers
Scaled wheels will cause
excessive wear to the brake blocks, and may jam causing skidding wheels
Describe spalling
arises when a piece of metal breaks loose from the wheel tread surface leaving a “crater”
Spalling is caused by
thermal damage, skidding or overstressing at the wheel/rail interface. A combination of one or more factors such as excessive vertical loads, excessive braking, incorrect wheel hardness and/or poor track and excessive speed resulting in high impact stresses
Spalling can cause
significant and detrimental brake block wear
Thermal cracks are caused by
thermal cycling (repeated heating and cooling of the wheel tread material)
Thermal cracks are generally caused by
dragging or sticking brakes, extended braking periods or overhanging brake blocks
If thermal cracks are evident, the brake on the vehicle must be
brake isolated and green carded for inspection
Describe Thermal cracks
generally run across the wheel tread
Describe fatigue cracks
generally caused by a manufacturing fauls and readily identified by a single crack
If any severe cracking is found, that extends through the rim of a wheel, is must result in
the vehicle being detached and immediately red carded for urgent inspection
Describe hollowed wheel tread
wearing on the flat tread face in a hollow due to the railhead being much smaller than the tread of the tyre
The maximum allowed hollowing is
3mm measured by placing a flange guage across the tread face and using a rule to measure down
If hollowed wheel tread is allowed to go beyond condemning limit, there is a danger of
the wheel flange striking track components such as fishplates, crossovers, points and rods
Possible flange defects
too sharp/thin, too high, have developed an Arris
Why is an arris a danger?
Possible it will strike the end of a points blade and either force the points open by “splitting” them or climbing over the blade and causing a derailment
Describe an arris
a sharp edge on the “top” of the wheel flange on the leading face
Types of Integrity inspections performed on trains
Brake function inspection, Mechanical condition, brake pipe continuity, roll-by inspection
Describe a full inspection
conducted before a train departs from a commencing station. Consists of a full mechanical examination of the train and air brake test
A full inspection must include
a brake pip leakage test, a continuity test, the compilation of a train inspection certificate
Describe a full continuity test
conducted to ensure that the locomotive driver has full and continuous control over the brake pipe following its disruption. Conducted at the rear of the train and may involve the use of an end of train telemetry device (EOT)
Describe a Modified Continuity test
conducted to ensure that the driver has continuous control over the brake pipe at the point to the read of that at which the brake pipe was disrupted. at the point of disruption for 3 vehicles
Describe a Roll-by inspection
conducted at terminals, on arrive or departure and at crossing points en-route Consists of an in-motion inspection of the condition of the passing train
A full inspection comprises of
an inspection of the operation of the brake and an inspection of the mechanical condition of the equipment on vehicles on the train
Normally, a full train integrity inspection is conducted following
the completion of the marshalling of the train consist
Duties of train Examiners
examine every vehicle, take appropriate action to effect repairs to vehicles, card vehicles for repairs if cannot be rectified, ensure wagons are not overloaded, report defects and damages to supervisor
On satisfactory completion of the brake pipe leakage test, the loco driving must
advise the examiner to commence the train test and with the train brake applied, the examiner must, after placing his safety tag on the loco independent brake hand, request protection, remove the reverser handle from the locomotive and proceed along the train to check the train
