How it works & Bulleid innovation

A steam engine is basically a method of turning pressurised steam created in the boiler into forwards and backwards motion via means of pistons and connecting rods to the wheels. However, a locomotive such as General Steam Navigation takes the basic principles to create a complex design to create power and efficiencies.

These pages aim to provide an overview of some of the design features and innovation incorporated within General Steam Navigation. 

Click on the links below to find out more:

Basic Steam Engine Principles

Click here to discover the basis principles of a steam engine.

The Bulleid Boiler

The Bulleid boiler design was a highly efficient steam raiser and “generally recognised as the best of all pacific boilers”. Read more about the design here.

The Crank Axle

The reciprocating motion from the piston must be transferred to rotary motion to drive the wheels. The motion from an inside cylinder is transferred via a crank axle.

Read more about the crank axle and how we are going to achieve replacing the missing crank axle on 21c11/35011 General Steam Navigation here.

Bulleid's Patented Chain Driven Valve Gear

The purpose of the valve gear on a steam locomotive is to control the flow, direction and amount, of steam passing into and out of the cylinders.
Bulleid's innovative patented chain drive valve gear is described here.

Bulleid - Firth - Brown wheels

One of Bulleid’s most instantly recognisable features on his Southern Railway locomotives are his BFB wheels.

They are described in more detail here.  

Trailing Trucks 

There were two designs of trailing trucks fitted to Bulleid Merchant Navy pacifics, our 21c11 / 35011 is unique amongst those  preserved in being itted with one of the fabricated type of trailing truck. 

Read more about the two types of trailing truck here.  

The Bulleid Merchant Navy Cab and Fittings

The Bulleid cab gave a better standard of comfort and protection for the engine crew than almost any other British locomotive then running.

Find out what all the cab fittings are here and how you can sponsor a part for 21c11 / 35011 here.

Electricity Generation, Lights and Engine Headsignals

Another recognisable feature of Bulleid pacifics was the electric lamps fore and aft and also within the cab. Electricity was generated on board by a “Stones steam generator”. 

Read about how the system worked here.

Sand Gun

One of GSNs unique features a Sand Gun fitted on the Firebox Back Plate

Read more about this feature ...