Interview Questions regarding to OHE(Overhead Equipment) Part 2
The rapidly evolving technology of the future holds potential for various job opportunities as it continuously undergoes technological advancements. Keeping this in mind, I have brought the second part of the question bank. We hope that after completing this, you will have a good chance of succeeding in OHE interviews. I have already published to first part of this series, Before reading this series you should watch the first series.
- For even no’s of tracks, versine is measured from
Individually measured for each track
- In regulated OHE, how much tension is kept in OHE
2000 kg
- In regulated OHE, Where anti-creep point is provided ?
Midway of tension length
- The reason of anti-creep arrangement is “To restrict the OHE movement …………
Along the track
- What is the initial sag is allow at the stringing temperature ?
No sag
- Which OHE system provide less push up due to passage of pantograph of the moving train
Compound catenary system
- Push up of OHE is depends upon
(a) Span length
(b) Speed of the train
(c) Weight of the OHE
- What do you mean by the elasticity of the contact wire ?
Amount of vertical lift corresponding to vertical static force
- In entire span length, elasticity of OHE will be
Minimum at support & maximum at mid span
- Pre sag in contact wire is given in regulated OHE due to
(a) Pantograph approaching mid span helps to make contact wire horizontal
(b) Improved current collection at higher speed
(c) Avoid hogging at low temperature
- Insulated overlap is required for
OHE sectioning purpose
- In AC traction, distance between two OHE’s conductor in insulated overlap is kept
500 mm.
- In AC traction, distance between two OHE’s conductor in un-insulated overlap is kept
200 mm
- Un-insulated overlap is provided in OHE because
To restrict tension length
- In AC traction, how many spans are required to construct an overlap on tangent track
Three span
- In AC traction, how many spans are required to construct an overlap on curve track
Four span
- Normally, insulated overlap are employed at the location
(a) SSP
(b) SP
(c) Booster transformer’s location
- In four span insulated overlap, the distance between the centre of the four span insulated over lap & anticreep should not be more than
800 m
- The normal desirable length of zone, where pantograph contacts both contact wires in overlap will be
6 m to 9 m
- In three span un-insulated overlap arrangement, center span or overlap span should not be less than
54 m
- Normally, which type of neutral section have been adopted by Indian Railways
(a) Overlap type
(b) PTFE type neutral section
(c) Short neutral section comprising section insulator assembly
- The length of PTFE type neutral section is
5.163 m
- PTFE stands for
Poly Tetra Floro Ethylene
- How many spans are required to consist an overlap type neutral section
5
- Stagger at PTFE type Neutral section assembly is
Zero or maximum 100 mm.
- On tangent track before neutral section, signal location should not be less than
400 m.
- On tangent track after neutral section, signal location should not be less than
200 m
- At the obligatory location, turn out contact wire is kept ….mm above from the main line contact wire
50 mm
- At section insulator location , encumbrance should not be less than
450 mm
- At the location of section insulator, stagger of contact wire should be
zero
- In AC traction , Which jumper distribute the current between catenary wire & contact wire
C jumper
- How many “C” jumpers are used in 1500 m tension length
3
- Distance of “C” jumper’s from the nearest mast is
5.6 m
- “F” jumpers are provided at
Insulated overlap
- “F” jumpers is also called
potential equalizer
- “G” jumper is used at
Both un insulated overlap & Turn out & Cross over
- Length of “C” jumper is
2.0 m
- Cross section area of “C” jumper is
50 sq. mm
- Cross section area of “G” jumper is
105 sq. mm(In IR), 150 sq. mm (In DFCCIL project)
- The arrangement of the cantilever assembly depends upon the
(a) Height of contact wire
(b) Setting distance
(c) Stagger
- Cantilever dimension “A” shows the distance between
Axis of bracket tube mast fitting & top of bracket tube
- Cantilever dimension “B” shows the distance between
Axis of vertical swivel & the axis of the catenary suspension bracket
- Cantilever dimension “C” shows the distance between
Axis of the vertical swivel to axis of register arm hook in horizontal position
- Cantilever dimension “D” shows the distance between
(d) The horizontal distance between the centre of register arm hook & the axis of the
catenary suspension bracket.
- In AC traction return current flows through
- In AC traction, track bonding is done upto the distance either side from the FP
1 km
- In AC traction, why track bonding is done upto 1 KM from either side of the FP
(a) Beyond this distance return current goes through RC
(b) Beyond this distance return current disappears into Earth
(c) Beyond this distance return current is not necessary to come upto TSS
- In 25 kV AC OHE, normal capacity of Lightning Arrester (heavy duty type)
42 kV
- Minimum earth resistance when not specified should not be more than
10 ohm
- Minimum earth resistance for 25 kV TSS should not be more than
0.5 ohm
- Minimum earth resistance for 25 kV switching station (SSP / SP etc) should not be more than
2 ohm
- The soil resistivity depends upon the
(a) Grain size of the soil
(b) Chemical composition of the soil
(c) Moisture contents
- Full form of RSJ mast
Rolled Steel Joist
- Full form of BFB mast
Broad Flanged Beam
- Full form of TTC mast is
Two /Three Track cantilever
- Size of RSJ Mast
152 mm x 203 mm
57.Size of BFB Mast on tangent track/single cantilever
152 mm x 152 mm
- Which is K- series mast
(a) K- 150 (b) K-200 (c) K-250
- Width of K-series mast
300 mm
- Width of TTC mast
300 mm
61.Size of “N” type portal
450 x 450 mm
- Size of “O” type portal
550 x 550 mm
- Size of “R” type portal
600 x 600 mm.
64.In BFB mast
Flange & depth (web) same
- In RSJ mast
Small flange & large web
