A - Alignment, Curves

Question 1

How do you calculate lateral acceleration?

Answer 1

a=v^2/R

Where v is speed and R is radius of curve

Question 2

What percentage of gravity is an acceptable lateral acceleration?

Answer 2

approx. 10%

Question 3

Apart from passenger discomfort list some problems that might occur if a train takes a corner too fast

Answer 3

Freight load can shift
Increase resistance due to wheel/rail contact
Wheels and rails deteriorate fast
Rails can tilt
Track can displace laterally
Increased noise
Derail
Overturn

Question 4

How can you tackle the problem of corners?

Answer 4

Place speed restrictions
Avoid tight radii
Cant

Question 5

Although large cants work for faster trains, can slower trains also run?

Answer 5

No
A slow train with a large cant would cause the same problems with wheel and rail wear
The result is a compromise

Question 6

What is the shortfall in cant for fast trains called?

Answer 6

Cant deficiency

Question 7

What is the maximum allowable lateral acceleration?

Answer 7

1.5ms^-2 (preferably <1)

As the suspension system will mean the passengers feel acceleration 20-40% greater than this

Question 8

What is the maximum cant in the UK?

Answer 8

150mm