(SEM VII) THEORY EXAMINATION 2022-23 RAILWAY, WATERWAY SND AIRWAY ENGINEERING

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.