Diesel = 8500 cal/l, while LNG = around 4500 cal/l.
That means that you’ll need almost twice the LNG to generate the same energy as with Diesel.
So when you talk about price, right now LNG is so low that buying twice the energy is still cost advantageous.
What’s likely to happen is that locomotives will go truly hybrid - LNG AND Diesel. When the price point on LNG gets to the point where it makes more sense to use Diesel, they will.
BNSF is looking to differentiate the supply chain in order to create price competition between sources.
Fish and foul, not fish or foul.
I think weight is a bigger consideration to a train over volume. That is what takes the energy to accelerate and lift over hills.
1 million BTU = 12.1 gallons LNG = 42.4 lbs LNG
1 million BTU = 7.2 gallons diesel = 51.5 lbs diesel
Diesel - less volume to carry but more weight vs LNG.