Yup, that's the pressurised oil/water burner type. Went through the same trials, issued on approval but ultimately they stuck with the Hydra as it was less complicated and squaddie-proof. Alec.
Good question! It isn't mentioned in the notes I have, I would suspect a heating oil, or a very very light motor oil (that would tend to coke a burner though), possibly paraffin itself. But it definitely isn't petrol. Alec.
Thanks. Is there any documents or description for the differences of the Hydra A to F? I presume this type of Hydra had a letter to identify it?
No but I am working on that. Thats an F-Type with a shorter baseplate and the manifold for the petrol burners. Two were supplied with each trailer for a total of 8 burners. Alec.
No technically the F is the whole assembly, the last iteration, but its the base for the one in the photo. The earlier style commonly used the D type "age" of components, with a different style of valve/handwheel and a lifting loop to assist carrying. Alec.