Anonymous
10/30/2025, 9:39:57 PM
No.2057479
>>2057011
It's all about energy efficiency and power to weight.
Diesel engines convert fuel (Chemical energy) -> Movement (Kinetic energy) at 40% efficiency maximum. Electric motors convert Electrical energy -> Kinetic energy at ~95% efficiency.
Also because they move power generation off the train to power plants & the grid, electric locos & EMUs are only limited by how much power they can put to rails. In diesels the limit is having a power pack & fuel tank that still fits in the train, which means less power than a full power plant.
>motorbikes & diesel cars remain nippy while carrying an engine
Motorbikes & cars are orders of magnitude lighter than trains, a single carriage bogie weighs nearly as much as a double-decker bus. Power requirements scale linearly with weight. More weight -> bigger engine -> bigger pistons with more inertia -> slower throttle response.
>Diesel trains can do regenerative breaking too with a small battery
Battery tech has only recently been able to do this. Even with Lithium chemistry it still has a weight penalty compared to pure electric. Plus batteries can only supplement diesel for a short-term boost before they need charging.
>>2057042
Nah, Voyagers have electric transmissions. There aren't many diesel-electric DMUs in the UK. The increased efficiency of transmission often doesn't make up for the added weight of the alternators and motors, especially at lower power outputs found in sub 100mph DMUs.
It's all about energy efficiency and power to weight.
Diesel engines convert fuel (Chemical energy) -> Movement (Kinetic energy) at 40% efficiency maximum. Electric motors convert Electrical energy -> Kinetic energy at ~95% efficiency.
Also because they move power generation off the train to power plants & the grid, electric locos & EMUs are only limited by how much power they can put to rails. In diesels the limit is having a power pack & fuel tank that still fits in the train, which means less power than a full power plant.
>motorbikes & diesel cars remain nippy while carrying an engine
Motorbikes & cars are orders of magnitude lighter than trains, a single carriage bogie weighs nearly as much as a double-decker bus. Power requirements scale linearly with weight. More weight -> bigger engine -> bigger pistons with more inertia -> slower throttle response.
>Diesel trains can do regenerative breaking too with a small battery
Battery tech has only recently been able to do this. Even with Lithium chemistry it still has a weight penalty compared to pure electric. Plus batteries can only supplement diesel for a short-term boost before they need charging.
>>2057042
Nah, Voyagers have electric transmissions. There aren't many diesel-electric DMUs in the UK. The increased efficiency of transmission often doesn't make up for the added weight of the alternators and motors, especially at lower power outputs found in sub 100mph DMUs.