About this previous year paper
TRANSPORTATION ENGINEERING – II (ECE603)
Section-wise Solved Answers & Notes
SECTION – A (10 × 2 = 20 Marks)
Very short, precise answers
(a) Sub-grade
Sub-grade is the natural soil prepared and compacted to support the pavement structure. It acts as the foundation of the track/road.
(b) Steel vs Cast Iron
| Steel | Cast Iron |
|---|---|
| High tensile strength | Brittle |
| Ductile | Low tensile strength |
| Used in rails | Used in base plates |
(c) A.N.C. and T.N.C.
• ANC (Absolute Negative Cant): Cant provided opposite to required cant.
• TNC (Total Negative Cant): Sum of provided cant and cant deficiency in opposite direction.
(d) Bearing plate
Bearing plate is a steel plate placed between rail and sleeper to distribute load uniformly and reduce wear on sleepers.
(e) Track drainage
Track drainage is the removal of surface and sub-surface water from railway tracks to maintain stability and prevent track failure.
(f) Marshalling yard
A marshalling yard is used for sorting and rearranging wagons to form new trains based on destination.
(g) Absolute block system
A system where only one train is allowed in a block section at a time, ensuring maximum safety.
(h) Interlocking
Interlocking is an arrangement that prevents conflicting movements of trains by mechanically or electrically linking signals and points.
(i) Track resistance
Track resistance is the force opposing the motion of a train, including rolling resistance, air resistance, gradient resistance, and curve resistance.
(j) Cant deficiency
Cant deficiency is the difference between equilibrium cant and actual cant provided when a train runs faster than equilibrium speed.
SECTION – B (Attempt Any FIVE) (5 × 10 = 50 Marks)
(a) Issues in rail fastenings
Rail fastenings secure rails to sleepers.
Issues include: • Loosening due to vibration
• Corrosion • Fatigue failure
• Maintenance difficulty • Thermal expansion effects
Proper fastenings improve safety, durability, and riding comfort.
(b) Concrete and pre-stressed concrete sleepers
Concrete sleepers: • Long life
• High stability • Suitable for high-speed tracks
Pre-stressed concrete sleepers:
• Higher strength • Crack resistance
• Better load distribution
Used widely in modern railway tracks.
(c) Super-elevation & negative super-elevation
Super-elevation: Raising outer rail on a curve to counter centrifugal force.
e=Gv2127Re = \frac{G v^2}{127 R}e=127RGv2
Negative super-elevation: When inner rail is raised (rare, used in special conditions).
Example:
For high-speed rail curves to reduce derailment risk.
(d) Types of railway yards
• Passenger yard – passenger trains • Goods yard – loading/unloading
• Marshalling yard – sorting wagons • Locomotive yard – engine maintenance
Example: Tughlakabad Marshalling Yard, Delhi.
(e) Aircraft characteristics affecting airport design
• Aircraft speed • Wing span
• Wheel load • Turning radius
• Landing & take-off distance
Example: Larger aircraft require longer runways and wider taxiways.
(f) Mechanical interlocking for two-line station
Mechanical interlocking uses levers, rods, and bars to ensure correct sequence of signal and point operation.
Example:
Signal cannot be cleared unless points are correctly set.
(g) Points and crossings
Used to divert trains from one track to another.
Components:
• Switch rails • Stock rails
• Frog (crossing)
Example: Turnouts at junction stations.
(h) Ballast
Ballast is broken stone placed under sleepers.
Functions:
• Load distribution • Drainage
• Track stability
Specifications: • Size: 20–65 mm
• Hard, angular, durable
Screening: Removal of fines to restore drainage.
SECTION – C (Attempt Any TWO) (2 × 15 = 30 Marks)
Q3. Runway Length Correction (Numerical)
Given:
• Landing length (sea level) = 3000 m • Take-off length (sea level) = 2500 m
• Elevation = 150 m • Aerodrome reference temp = 25°C
• Standard temp at elevation = 14.025°C • Effective gradient = 0.5%
(i) Elevation correction
Increase 7% per 300 m: =150/300×7=3.5%= 150/300 \times 7 = 3.5\%=150/300×7=3.5%
(ii) Temperature correction
ΔT=25−14.025=10.975∘C\Delta T = 25 - 14.025 = 10.975^\circ CΔT=25−14.025=10.975∘C
Increase 1% per °C:
=10.975%= 10.975\%=10.975%
(iii) Gradient correction Increase 20% per 1% gradient:
=0.5×20=10%= 0.5 \times 20 = 10\%=0.5×20=10%
(iv) Corrected runway length (take-off governs)
L=2500×(1+0.035+0.10975+0.10)L = 2500 \times (1+0.035+0.10975+0.10)L=2500×(1+0.035+0.10975+0.10) L≈3110 m (approx.)L \approx \boxed{3110 \text{ m (approx.)}}L≈3110 m (approx.)
Q4. Harbour – Design Factors
Harbour: A sheltered water area for ships to anchor safely.
Design factors:
• Location & depth • Wave action & tides
• Soil condition • Wind direction
• Cargo type • Future expansion
Example: Mumbai Harbour.
Q5. Classification & Types of Signals
Criteria for classification • Function
• Location • Method of operation
• Colour/light
Types of signals
• Semaphore signals • Colour light signals
• Distant signals • Home signals
Semaphore signal (working)
Uses mechanical arms:
• Horizontal – Stop • Inclined – Caution
• Vertical – Clear
(Neat block diagram to be drawn in exam)