Interesting video of an Allis Chalmers fuel cell powered tractor over 60 years ago. And here I thought fuel cell powered stuff was something recent. According to the video, this was 90% efficient vs. diesel power at 40%. Too bad they didn't develop it further - who knows what impact this would have had industry wide. Not just tractors but everything else that uses IC engines. My guess is that fossil fuel was so abundantly cheap they could not build this at a price level to compete even if it was twice as efficient.