When looking at Warship and Transport ship construction and propulsion during the 20th Century the problem of time required to build up steam pressure can alter the course of either a surprise attack, range in combat condition and numerous other factors. What I am wondering is the changes needed to increase the size and capability of Diesel engines to make them a viable alternative.
Technology progression in propulsion goes as follows.
Steam engines with literally pistons ie, steam is generated by burning coal, oil to create pressure that drives a piston in order to power the ship.
late 19th century saw intrduction of these kind of engines and they still got used in WW2 for some cargo ships. reliable if inefficent in terms of power to weight.
More advanced forms of this engine used multiple expansion engines to improve efficency.
Steam Turbines. These engines used again coal or oil to generate steam at pressure that was then directed into a turbine that spun the propeller shaft. The higher the pressure the greater the power but this comes as with the multiple expansion engines with a time delay on generating the requisite power. ie a cold boiler takes time to start up. Even a boiler running at lower pressures due to lower power needs takes time to react. Also the higher the boiler pressure the greater the risk of failure. Steam failure is not forgiving.
Turbo Electric drive. THis simply uses the steam turbines to generate electricity that is then used to turn the propeller shaft. This has advantages and disadvatages especially in terms of damage control and other aspects but is relatively inefficent. It is still viable especially if a nuclear reaction is used to start the steam production.
At the same time as turbines came about the first diesel engines got installed in submarines initially. These engines in Submarine use had the advantage of using oil only and not needing the large smoke stack etc. The power to space ratio was the only major issue and one that persisted for many years.
Diesel engines began using superchargers and turbo chargers to increase the power to space and power to weight issues. Turbochargers and superchargers both require sophisticated machining and initially came with bad reliability issues.
The advantages for a warship if large diesels are developed earlier are especially relevant to fast change from efficent cruise to high power for combat etc.
My question is how early could large diesel engines of high power to weight and space come about and could earlier improvements to turbochargers or Superchargers ina marine setting have a flow on effect to aircraft.
BTW the diesel engine in a marine setting also works wonders as a form of power for cargo ships.
Notable diesel engined ships include.
KM Graf Spee which used 8 MAN diesels to generate 53,000SHP which is not a huge amount but did give very long range.
In order for Battleship use of Diesels they need to be able to generate much more power for installed space. IE the kind of power needed is 160,000 hp for the KGV class or 220,000 hp for Iowa classes. THe Queen Elizabeth class ships such as HMS Warspite need far less power with 75,000 being required.
The other aspect of the design of Marine diesels is the form of connecting to the shafts. IE diesel electric has many advantages with weight being a disadvantage.
Is it possible to get Diesel engines seen as a practicle alternative to Steam Turbine for WW2 warships and Cargo vessels. Who or What needs to happen. BTW a Liberty lass cargo vessel only needs 2500 hp which is fairly easy to do. What it gains from diesel is reduced crewing I would think.
Technology progression in propulsion goes as follows.
Steam engines with literally pistons ie, steam is generated by burning coal, oil to create pressure that drives a piston in order to power the ship.
late 19th century saw intrduction of these kind of engines and they still got used in WW2 for some cargo ships. reliable if inefficent in terms of power to weight.
More advanced forms of this engine used multiple expansion engines to improve efficency.
Steam Turbines. These engines used again coal or oil to generate steam at pressure that was then directed into a turbine that spun the propeller shaft. The higher the pressure the greater the power but this comes as with the multiple expansion engines with a time delay on generating the requisite power. ie a cold boiler takes time to start up. Even a boiler running at lower pressures due to lower power needs takes time to react. Also the higher the boiler pressure the greater the risk of failure. Steam failure is not forgiving.
Turbo Electric drive. THis simply uses the steam turbines to generate electricity that is then used to turn the propeller shaft. This has advantages and disadvatages especially in terms of damage control and other aspects but is relatively inefficent. It is still viable especially if a nuclear reaction is used to start the steam production.
At the same time as turbines came about the first diesel engines got installed in submarines initially. These engines in Submarine use had the advantage of using oil only and not needing the large smoke stack etc. The power to space ratio was the only major issue and one that persisted for many years.
Diesel engines began using superchargers and turbo chargers to increase the power to space and power to weight issues. Turbochargers and superchargers both require sophisticated machining and initially came with bad reliability issues.
The advantages for a warship if large diesels are developed earlier are especially relevant to fast change from efficent cruise to high power for combat etc.
My question is how early could large diesel engines of high power to weight and space come about and could earlier improvements to turbochargers or Superchargers ina marine setting have a flow on effect to aircraft.
BTW the diesel engine in a marine setting also works wonders as a form of power for cargo ships.
Notable diesel engined ships include.
KM Graf Spee which used 8 MAN diesels to generate 53,000SHP which is not a huge amount but did give very long range.
In order for Battleship use of Diesels they need to be able to generate much more power for installed space. IE the kind of power needed is 160,000 hp for the KGV class or 220,000 hp for Iowa classes. THe Queen Elizabeth class ships such as HMS Warspite need far less power with 75,000 being required.
The other aspect of the design of Marine diesels is the form of connecting to the shafts. IE diesel electric has many advantages with weight being a disadvantage.
Is it possible to get Diesel engines seen as a practicle alternative to Steam Turbine for WW2 warships and Cargo vessels. Who or What needs to happen. BTW a Liberty lass cargo vessel only needs 2500 hp which is fairly easy to do. What it gains from diesel is reduced crewing I would think.
