Beyond The Sprues

Modelling => Ideas & Inspiration => Engineering Dept. => Topic started by: kengeorge on December 18, 2025, 01:42:13 AM

Title: A question of horsepower
Post by: kengeorge on December 18, 2025, 01:42:13 AM
Here is my appeal to the hives minds on here, I am looking for an alternative to gas turbine power, namely diesel for a design I am creating. Currently my design has turbine electric power up to 4,500hp, but I'm looking at a diesel engine(s) alternative up to that power rating. Also I need to consider size, weight, reliability and fuel consumption against the turbine option.
What diesel engine(s) would be recommended?

TIA
Ken
Title: Re: A question of horsepower
Post by: Jeffry Fontaine on December 18, 2025, 01:50:26 AM
Napier Deltic
Title: Re: A question of horsepower
Post by: GTX_Admin on December 18, 2025, 01:50:47 AM
Are we talking aircraft or ground vehicle here?  What era?
Title: Re: A question of horsepower
Post by: kengeorge on December 18, 2025, 03:04:49 AM
Hovercraft and present day
Title: Re: A question of horsepower
Post by: Kerick on December 18, 2025, 07:23:15 AM
Turbine might be more efficient if traveling at a constant speed for long periods. The diesel would work better at constantly changing speeds, especially for periods of idling. Weight might be a factor in a hovercraft too.
Title: Re: A question of horsepower
Post by: elmayerle on December 18, 2025, 07:29:16 PM
Turbine might be more efficient if traveling at a constant speed for long periods. The diesel would work better at constantly changing speeds, especially for periods of idling. Weight might be a factor in a hovercraft too.
Yeah, the railroads found that out when they tested gas turbine locomotives.  Union Pacific tested them extensively, as well as steam turbine engines.  You can appreciate why they had an attraction to high-power steam locomotives (Big Boys) and high-power diesel locomotives (Cenntennials).  If you go with diesel prime mover(s), I'd look at what is used by present day GE, EMD, et al. locomotives.  If you adapt from a Stage IV diesel, it would be quite clean.
Title: Re: A question of horsepower
Post by: kengeorge on December 18, 2025, 09:14:58 PM
It seems like I'll stick to turbine power instead of diesel for my design. Thank you all for your input, it is greatly appreciated

Ken
Title: Re: A question of horsepower
Post by: apophenia on December 19, 2025, 06:28:53 AM
Turbine might be more efficient if traveling at a constant speed for long periods. The diesel would work better at constantly changing speeds, especially for periods of idling. Weight might be a factor in a hovercraft too.

It seems like I'll stick to turbine power instead of diesel for my design...

A third alternative would be to go gas turbine/electric hybrid. That allows the turbines to charge generators at relatively constant rpm with the electric drive motors handling the changing speeds.
Title: Re: A question of horsepower
Post by: kengeorge on December 20, 2025, 09:56:27 AM
apophenia, I have after all concideration, I've selected the powertrain, it will be Gas turbine/electric power. Compact, lightweight and as you said, tubines run at a constant RPM, to charge generators and let the electric motors do the heavy lifting.
Thank you everyone

Ken