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andym

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Posts posted by andym

    Steev

    in American Vehicles

    Posted

    Shock is usually the best thing for things like this, continuous high torque is less effective.  Find a spanner that fits properly (important with a brass fitting), knock it first clockwise and then anti-clockwise.

    Andy

    rolls royce horizontally opposed

    in Tracked vehicles

    Posted

    10 hours ago, Jerrykins said:

    I recall the FD12 was selected for the Hunt class because it's characteristics of low vibration & low magnetic signature were necessary when sweeping above active mines.  The FD12 generated electrical power at 1800 r/min, which equates to 360 firing cycles per second, vibration was further minimised by mounting the gen set on a raft with two sets of mounts transmitting little vibration to the hull/sea. Three gen sets were mounted in the hull above sea level further reducing noise transmitted into the water. The crankcase was cast in non-magnetic aluminium, as were many of the auxiliary casings, stainless steel conn rods & c/shafts etc all adding to low magnetic signature. Part way through development Foden decided the work was not for them & the MoD transferred the work to R-R Crewe, presumably because R-R had considerable experience of 2 strokes with the K60, which had proven to be the best 2 stroke in UK military service. When sweeping the ship employed electric only propulsion making the ship was pretty stealthy, noise-wise. It was during the Iraq / Iran war that the Hunt class cleared the passage of mines into Kuwaiti waters for the allies, they did the job well without loss, they were the best ship available to do the job.

    I think you're getting confused between the Hunts and the Sandowns - the Hunts have never had electric propulsion.

    Andy

    rolls royce horizontally opposed

    in Tracked vehicles

    Posted

    13 minutes ago, radiomike7 said:

    Yes and no, if the price of fuel is not an issue then it makes sense but the two stroke cycle is not as efficient as a four stroke, ask anyone who has run a Scammell Crusader or a Bedford TM with a Detroit. Even with conventional cam driven poppet valves for the exhaust the Detroit was behind a four stroke. 

    I believe the emissions were mainly a problem caused by the excess oil in the bores needed to ensure the rings did not seize when passing the inlet ports, the Deltic locomotives were known for oil fires in the exhaust drum after a period of idling.

    There's a company in the USA (whose name I can't remember) who are getting research funding from the DoD to look into high efficiency electronically managed two-strokes, which they claim are more efficient than four-strokes.  Times have changed since Detroit diesels!

    Andy

    rolls royce horizontally opposed

    in Tracked vehicles

    Posted

    That is indeed a K60, presumably from the Swedish S tank.  Interesting to see it in a different configuration to "normal"; the oil tank has swapped sides, the hydraulic pump has been blanked off and there only seems to be one alternator, the other having been replaced by what looks like a toothed belt pulley..

    Andy

    Today’s job!

    in Tracked vehicles

    Posted · Edited by andym

    12 hours ago, diesel1 said:

    Was meant be short clip of the abbot firing, cannot seem to load video from iphone

    Ah - I wondered if it was just me thinking "what video"?

    Andy

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