Maintenance Manual for BG Coaches of ICF design

Maintenance Manual for BG Coaches of ICF design: The main constructional and design features of the ICF/RCF all-coil bogies, used on mainline BG coaches are briefly described in the following paragraphs.

Description	Parameters
Maximum Axle load bearing capacity	16.25t, 13t
Wheel base	2896mm
Wheel diameter (New)	915mm
Axle guidance	Telescopic axle guide with oil damping
Primary suspension	Coil spring
Secondary suspension	Coil spring
Shock absorbers	i) Vertical dashpot in primary suspension. ii) Hydraulic double acting vertical shock absorber in secondary suspension
Transfer of coach body weight	Through bogie side bearer pitched at 1600mm

ALL-COIL ICF BOGIE

The bogies being currently manufactured by ICF/RCF which have been accepted as standards of the Indian Railways and are of an all welded light weight construction. Axles are located on the bogie by telescopic dash pot and axle guide assemblies.

Helical coil springs are used in both the primary and the secondary stages. The axle guide device provides viscous damping across primary springs while hydraulic dampers are provided across the secondary stage.

Dampers are protected against misalignment by resilient fittings. Isolation of vibration is effected by rubber pads in primary and secondary suspension.

Deflection due to the tare weight is almost equally divided between axle and bolster springs. Weight of coach body is transferred to its bogie by side bearers pitched 1600 mm apart. Sidebearers consist of lubricated metal slides immersed in oil baths.

No vertical weight transfer is effected through bogie pivot and the pivot acts merely as a centre of rotation and serves to transmit tractive/braking forces only.

BOGIE ASSEMBLY

The bogie frame and components are of all-welded light construction with a wheel base of 2.896 metre. The wheel sets are provided with self-aligning spherical roller bearings mounted in cast steel axle box housings. Helical coil springs are used in both primary and secondary suspension.

The weight of the coach is transferred through side bearers on the bogie bolsters. The ends of the bogie bolsters rest on the bolster helical springs placed over the lower spring beam suspended from the bogie frame by the inclined swing links at an angle 7 0 . Hydraulic shock absorbers and dash pots are provided in the secondary and primary suspensions respectively to damp vertical oscillations.

AXLE BOX GUIDE WITH DASH POT ARRANGEMENT

Axle box guides are of cylindrical type welded to the bottom flanges of the bogie side frame with close dimensional accuracy. These guides together with lower spring seats located over the axle box wings, house the axle box springs and also serve as shock absorbers.

These guides are fitted with guide caps having nine holes of diameter 5 mm equidistant through which oil in the lower spring seat passes under pressure during dynamic oscillation of coach and provide necessary damping to primary suspension to enhance better riding quality of coach. This type of rigid axle box guide arrangement eliminates any longitudinal or transverse relative movement between the axles and the bogie frame.

The quantity of oil required to achieve 40 mm oil level above the guide cap in modified arrangement is approximately 1.6 liters and in unmodified arrangement is approximately 1.4 liters. As it is not possible in open line to distinguish between modified and unmodified arrangements, 40 mm oil level is standardised for both.

AIR VENT SCREWS

On the bogie side frames, directly above the dash-pots, tapped holes are provided for replenishing oil in the dash pots. Special screws with copper asbestos washers are screwed on the tapped hole to make it air tight.

BOGIE BOLSTER SUSPENSION

The bolster rests on the bolster coil springs – two at each end, located on the lower spring beam which is suspended from the bogie side frame by means of bolster-springsuspension (BSS) hangers on either side. The two anchor links diagonally positioned are provided with silent block bushes. The links prevent any relative movement between the bogie frame and coach body.

SPRINGS

In ICF bogie, helical springs are used in both primary and secondary suspension. The springs are manufactured from peeled and centreless ground bar of chrome vanadium/chrome molybdenum steel conforming to STR No. WD-01-HLS94 (Rev.1)

CENTRE PIVOT ARRANGEMENT

The centre pivot pin joins the body with the bogie and transmits the tractive and braking forces on the bogies. It does not transmit any vertical load. It is equipped with rubber silent block bushes which tend to centralise the bogies with respect to the body and, to some extent, control and damp the angular oscillations of the bogies.

SIDE BEARERS

The side bearer arrangement consists of a machined steel wearing plate immersed in an oil bath and a floating bronze-wearing piece with a spherical top surface kept in it, on both sides of the bogie bolster. The coach body rests on the top spherical surface of these bronze-wearing pieces through the corresponding attachments on the bottom of the body-bolster. The whole arrangement is provided with a cover to prevent entry of dust in the oil sump.

Wear limit for wearing plate

Wear limit for wearing piece

New size	Shop renewal size	Condemning size
45mm	43.5mm	42mm

ANCHOR LINKS

The floating bogie bolster which supports the coach body is held in position longitudinally by the anchor links which are pinned to the bolster sides and the bogie Transoms. One anchor link is provided on each side of the bolster diagonally across.

The links can swivel universally to permit the bolster to rise and fall and sway side wards. They are designed to take the tractive and braking forces. The anchor links are fitted with silent block bushes.This is a synthetic rubber bush fitted in anchor link and center pivot of ICF bogies to transmit force without shock and reduce noise.

BRAKE RIGGING

Brake rigging is provided to control the speed of the coach by transferring the braking force from the brake cylinder to the wheel tread. Brake rigging can be divided into two groups i.e. Bogie mounted brake rigging and coach under frame mounted brake rigging.

CONVENTIONAL AIR BRAKE COACH POWER CAR

TYPE OF COACH	BUILDER	TARE WEIGHT IN TONNES	% OF BRAKING
POWER CAR TO WLRRM6-9-0-601	ICF	53.7	118
HIGH CAPACITY POWER CAR	ICF	60	105.6

TYPE OF COACH	BUILDER	TARE WEIGHT IN TONNES	% OF BRAKING
WGACCW	ICF	50.0	114.8
	RCF	49.1	120.9
WGACCN	RCF	50.1	118.6
WGSCZAC	ICF	49.3	123.7
WGFAC	ICF	49.7	119.5
WGFSCZAC	ICF	50.0	118.8

CONVENTIONAL AIR BRAKE COACH NON AC COACHES

TYPE OF COACH	BUILDER	TARE WEIGHT IN TONNES	% OF BRAKING
GENERAL SECOND  CLASS	ICF	36	120
	RCF	37.4	115.5
SECOND DAY COACH	ICF	37	116.7
	RCF	37.3	115.8
SLEEPER	ICF	39.5	109.3
	RCF	39.45	109.5
FIRST CLASS	ICF	41.8	103.3
SLR	ICF	40.6	106.4
	RCF	40.0	108.0
SCNLR	ICF	41.0	105.3
PANTRY CAR	ICF	41.3	104.6

EQUALISING STAYS

This device has been provided on bogies between the lower spring plank and the bolster to prevent lateral thrust on the bolster springs which have not been designed to take the lateral forces. These links have pin connections at both ends and, therefore, can swivel freely.

BOLSTER SPRING SUSPENSION HANGERS (BSS HANGERS)

In the secondary suspension, the bolster is supported on helical coil springs which are placed on the lower spring plank. The lower spring plank is suspended from the bogie side frame through BSS hangers on hanger blocks.

SHOCK ABSORBERS

Hydraulic shock absorbers with capacity of ± 600 kg at a speed of 10 cm/sec. are fitted to work in parallel with the bolster springs to provide damping for vertical oscillations.