Opinion & Answer Part 18: Gas & Steam Turbine Locomotive

 

What are gas & steam turbined locomotives? How they work and run on gas and steam powered turbine engines? Well folks, today we get to take a dive into these two questions as we explore steam and gas powered turbined locomotives on this edition of Opinion & Answer: Part 18. 

First Question: What is a Gas turbine locomotive?

• A locomotive that runs a gas turbine engine to power its wheel. Meaning that a gas turbine train typically consists of two power cars (one at each end of the train), and one or more intermediate passenger cars. There is three types of Gas turbines engines, 1)Gas Turbine-mechanical,2)Gas turbine-Electric & 3) Coal-firing.

Second Question: What is a Steam Turbine Locomotive? 

A steam locomotive that is powered by a steam turbine in order to drive its wheels.

Advantages & Disadvantages of Gas & Steam Turbine Locomotives

1. Gas Turbine Locomotives

1. Advantage-Gas Turbine Locomotives 
• A gas turbine offers some advantages over a piston engine. There are few moving parts, decreasing the need for lubrication and potentially reducing maintenance costs, and the power-to-weight ratio is much higher. A turbine of a given power output is also physically smaller than an equally powerful piston engine, so that a locomotive can be extremely powerful without needing to be inordinately large.
2. Disadvantage- Gas Turbine Locomotives
• However, a gas turbine's power output and efficiency both drop dramatically with rotational speed, unlike a piston engine, which has a comparatively flat power curve. This makes GTEL systems useful primarily for long-distance high-speed runs. Additional problems with gas turbine-electric locomotives include the fact that they are very noisy and produce such extremely hot exhaust gasses that, if the locomotive were parked under an overpass paved with asphalt, it could melt the asphalt.

2. Steam Turbine Locomotives

• Advantages
• High efficiency at high speed.
• Far fewer moving parts, hence potentially greater reliability.
• Conventional piston steam locomotives give a varying, sinusoidal torque, making wheelslip much more likely when starting.
• The side rods and valve gear of conventional steam locomotives create horizontal forces that cannot be fully balanced without substantially increasing the vertical forces on the track, known as hammer blow.

• Disadvantages
• High efficiency is ordinarily obtained only at high speed and high power output (though some Swedish and UK locomotives were designed and built to operate with an efficiency equal to or better than that of piston engines under customary operating conditions including part-load). Gas turbine locomotives had similar problems, together with a range of other difficulties.
• Peak efficiency can be reached only if the turbine exhausts into a near vacuum, generated by a surface condenser. These devices are heavy and cumbersome.
• Turbines can rotate in only one direction. A reverse turbine must also be fitted for a direct-drive steam turbine locomotive to be able to move backwards.

Real World Examples-Gas Turbine Locomotives

1. Gas turbine-Mechanical
1. -Sweden
2. -Czechoslovakia
2. Gas turbine-Electric
1. -Switzerland
2. -Russia
3. -Canada 
3. Coal-firing & Gas turbine-Electric
1. United States
4. Gas Turbine Mechanical & Electric
1. France 
5. Gas Turbine Mechanical, Electric & Coal Firing
1. United Kingdom

That's all for this part of Opinion & Answer. Join us next Friday for Part 19 where we discussed geared steam locomotive. 

All a Board!

Conductor Wolf