SECTION A (2 Marks Each)
(a) Requirements of Permanent Way Formation
Permanent way formation should be strong, well-drained, stable, and capable of distributing train loads safely to the ground while maintaining proper alignment and level.
(b) Need of Narrow Gauge in Mountainous Country
Narrow gauge is preferred in hilly areas because it requires less land, allows sharper curves, reduces construction cost, and suits difficult terrain.
(c) Merits of Electric Traction
Electric traction offers high efficiency, greater speed, less pollution, low maintenance cost, and better acceleration.
(d) Push or Pusher Gradient
Pusher gradient is recommended when steep gradients cannot be avoided and additional locomotives are required to push trains uphill.
(e) Purpose of Wing Walls
Wing walls support retaining walls and guide the flow of water smoothly near bridges and culverts.
(f) Crossing Clearance
Crossing clearance is the minimum distance maintained between tracks at a crossing to ensure safe train movement.
(g) Interlocking
Interlocking is a safety arrangement that prevents conflicting train movements by controlling signals and points.
(h) Landing and Take-Off Along Head Winds
Aircraft take off and land along head winds to reduce ground speed and runway length requirement.
(i) Determination of Aircraft Capacity
Aircraft capacity is determined based on runway length, apron space, terminal facilities, and air traffic demand.
(j) Semi-Natural Harbours
Semi-natural harbours are naturally protected harbours that require some artificial structures for safe anchorage.
SECTION B (10 Marks Each – Any Three)
(a) Organizational Structure of Indian Railways
Indian Railways is headed by the Railway Board under the Ministry of Railways. It is divided into zones, divisions, and departments. Each zone is managed by a General Manager, and divisions are controlled by Divisional Railway Managers. Departments handle operations, engineering, electrical, mechanical, and commercial functions.
(b) Necessity and Types of Gradient in Railways
Gradient is necessary to overcome natural ground slope and ensure smooth train operation. Types include ruling gradient, momentum gradient, pusher gradient, and limiting gradient. Indian Railways specifies permissible gradient values based on terrain and gauge.
(c) Super Elevation and Speed on Curve
Super elevation is provided to counteract centrifugal force on curves. It depends on speed, gauge, and radius of curve. Maximum permissible speed ensures passenger comfort and safety, while transition length allows gradual introduction of super elevation.
(d) Basic Runway Length
Basic runway length is the length required under standard atmospheric conditions at sea level. Corrections are applied for elevation, temperature, and gradient. Three cases include take-off, landing, and balanced field length.
(e) Sounding and Its Methods
Sounding is the process of measuring water depth. Methods include sounding rod, lead line, echo sounding, and electronic depth recorders.
SECTION C (10 Marks Each)
Q3 (a) Cross-Section of Double Line Permanent Way (BG)
A typical cross-section includes rails, sleepers, ballast, formation width, cess, embankment slope, and drainage arrangement to ensure track stability.
Q3 (b) Types of Spikes and Requirements of Good Spike
Types include dog spike, screw spike, round spike, and elastic spike. A good spike should provide firm grip, resist loosening, and not damage sleepers.
Q4 (a) Determination of Maximum Speed on Curved Track
Maximum speed is determined considering radius of curve, gauge, super elevation, cant deficiency, and safety limits prescribed by Indian Railways.
Q4 (b) Relation Between Super Elevation, Speed, and Radius
Super elevation is directly proportional to square of speed and gauge, and inversely proportional to radius of curve.
Q5 (a) Absolute Block System
Absolute block system ensures only one train occupies a block section at a time. It improves safety and reduces collision risk. It is used for both single and double lines.
Q5 (b) Limitations in Achieving High Speed
Limitations include track curvature, gradient, signalling system, rolling stock design, braking efficiency, and maintenance standards.
Q6 (a) Runway Length Correction
Runway length is corrected for altitude, temperature, and gradient. Increased altitude and temperature require longer runways for safe aircraft operation.
Q6 (b) Airport Service Equipment
Service equipment includes refuelling units, towing tractors, passenger buses, baggage handling systems, fire-fighting vehicles, and lighting systems.
Q7 (a) Coastal Structures
Coastal structures include breakwaters, groynes, sea walls, and jetties. They protect shorelines and support navigation.
Q7 (b) Sea Walls and Riprap
Sea walls protect coastlines from wave action, while riprap consists of loose stones placed to prevent erosion.
