I agree with Tony that QF relates to ammunition. In the case of the 18-pdr being referred to, 'QF' in the nomenclature stands for 'Quick Firing' which indicates the means of obturation, that is, the method by which the propellant gases are prevented from escaping to the rear. In the case of QF guns and howitzers, this was primarily a brass cartridge case that expanded tight against the wall of the breech while the projectile is in the barrel, but then relaxes slightly once the projectile has exited the barrel and the pressure within has returned to 'normal', thus allowing easy extraction. (QF cartridge primers have an internal ball which blocks the primer flash hole, preventing gas escape back through the primer pocket). In any event, 'QF' has nothing to do with the means of buffering the recoil or returning the ordnance to the firing position - what the museum is calling the recuperator. In fact, it is the buffer that controls the barrel recoil and the recuperator which returns the barrel to the firing position.
The comment about asbestos rope is a little more perplexing, and one I cannot find a definitive answer for. The use of asbestos rope around the buffer and recuperator is not referred to in either the 1913 or 1923 manuals and handbooks for the 18-pdr, or the 1923 textbook of service ordnance. Trawin's 'Early British QF Artillery' - a highly detailed reference - does not mention the use of rope. Various forums have comments which range from the prevention of overheating to protection from shrapnel, but none provide any reference to a source. So if an MLU member has an official reference to wrapping the buffer and recuperator (B&R) in asbestos rope, please share it here!
We might explore this a little further. Dave has pointed out that, if it is to prevent the B&R from overheating, then it must be heat from an external source such as the barrel. Good observation, as such a wrapping would not assist in reducing heat generated from within the B&R - quite the opposite, it would retain the heat, as the action of the buffer piston and the movement of the mineral oil back and forth must generate a certain amount of heat. I don't know how much heat is generated within the B&R, but it is possibly not all that much given that, in an extreme emergency, pure water can be used as a short-term substitute for the oil. So as far as I'm concerned, Dave's comment that the asbestos rope is there to insulate the B&R from the rising heat of the barrel is looking like the most likely. Perhaps it is also there to prevent the mineral oil from becoming more viscous in cold climatic conditions when the gun is not firing, ie it acts as an insulator under all conditions?
Mike
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