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antarmike

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Everything posted by antarmike

  1. According to C and U recovery vehicles have to be wheeled vehicles. There is no provision for a tracked recovery vehicle. To be a recovery vehicle the crane or lifting device must be fitted to lift and carry some of the weight of the casualty as it travels. The side mounted position of the FV434 Hiab does not meet this requirement.
  2. Waste of time working on a solution for the brakes then! Whatever you do you can't make them legal. Having said that if people are going to continue to disregard the law, and brakes can be fairly easily be improved to bring them up to standard it is a better situation, but still far from ideal.
  3. My mistake then, I though they had swivelling drivers seat, two steering wheels and in either direction one axle trailed, and self centred on the castor angle. in effect only one axle steered depending on direction of travel. I accept I may have this wrong/
  4. Does the maximum C and U width of 2.55M apply to your vehicle,if not why not? and how wide is yours in reality? Have you fitted a compliant secondary braking system?
  5. depends whether the legs are facing away from or towards the direction of pull.....
  6. Yes but a walking camel has a higher ground pressure than one which has decided to lie down and stubbornly refuses to get up.... That ground pressure would be hard to beat!
  7. another possible cause of total brake failure would be breaking up of the brake drum itself. Again I cannot say whether this was a serious problem in service, but certainly the manual emphasises the need for careful inspection for signs of cracking Quote" 5.6 BRAKE DRUM INSPECTION When renewing brake bands, or carrying out steering unit adjustments, the steering unit brake drums must be inspected for signs of cracking, especially around the oil feed holes. Any sign of cracking must be reported to the repair section SNCO." Again, is the amateur mechanic aware of this and actively doing this check? As the 432's become older, presumably if this is a fatigue problem, it is an event that grows ever more likely.
  8. I am not familiar but gearbox end seems to be external spline into internal spline on drive shaft. The bolts appear to be on the outboard end of the drive shafts. Can anyone confirm this?
  9. More a case of bolts coming loose, to the point where the securing bolts shear.
  10. http://www.fv432.co.uk/Documents/Documents%20PDFs/fv430seriestech/Chapter%205%20Steering.PDF quote"If an output shaft breaks in normal bevel pinion differential the vehicle has no drive, but with a controlled differential the vehicle still has drive in a straight line, providing one brake is applied and the drum is stopped. However, application of one steering lever will grve a different speed of drive to the serviceable side, than would the application of the other steering lever." and quote" 5.8 STEERING UNIT ALIGNMENT It is VITAL that the steering unit (original or new) is re-aligned to the final drives when fitted to the vehicle. It is important that steering unit output shafts are aligned to within 0.015" in both the horizontal and vertical planes; and that the angular displacement is within 0.030" . WARNING If the steering unit alignment is not checked and adjusted, the solid drive shafts will begin to loosen the coupling securing bolts. Should these bolts sheer and the couplings disengage, ALL STEERING AND BRAKING WILL BE LOST." That doesn't sound like a highly unlikely event, How many amateur mechanics have access to the necessary gauges, or associated skill and patience, etc to carry this operation out to the required degree of accuracy? How many have changed steering unit having never read these instructions? How many 432's are out there with the bolts coming loose at this very minute?
  11. 434 must be heavier, and Abbot? A one solution which fits all would be nice.
  12. According to the book unladen is 13.74 Tonnes, and its weight laden is 15.28 tonnes .
  13. Presumably, when we talk about drive shaft failure leaving no brakes, we are talking about the output shafts shown green on this diagram?
  14. Presumably some form of VOSA inspection would be required before registration. Or by independant engineers report. more food for thought, Discussion welcomed.
  15. If this discussion is to move forward in a new direction, perhaps someone with the technical books can give us a full description of the steering and braking. We know that a secondary braking system is required. (this is not necessarily the same as a handbrake.) Some vehicles have a handbrake that isn't a ratchet handbrake, and these can be feathered on and off, so probably count. It is unlikely that a ratchet handbrake would suffice since it is my understanding that the secondary brake has to allow for the driving for short distance on road, in traffic, to a place of safety, following failure of the primary braking system. Although a ratchet brake can be feathered on, they cannot be feathered off. , only sudden total release. We know, if you don't mind looks, resiting the exhaust can bring the vehicle down to under 2.55m (or so I am told) Mk1's apparently being legal width. Not much help to all the other overwidth Armour I know, but a sensible start to lawful use of FV432 on the road. Lets have a sensible technical discussion as to how to set about modifying the brakes to comply. People say it would be possible, let us examine that claim. I see much more chance in converting FV432 to legal standards, than I do persuading the government to re-write C and U regs etc. , so that a few boys can play with their toys. Who wants to kick off with a practical suggestion as to how to modify the brakes?
  16. I have to say I don't think the tyres are tight on the chocks.
  17. Yep, should be there, I am now off to try and get a Pacific (Dragon Wagon) booked in!
  18. Humber Mk IV - 10.50 x 20 RF this is 10 1/2" wide tyre on 20" rim Humber Scout Car - 9.00-16 or 9.25-16 this is 9 or 9 1/4" wide tyre on 16" diameter rim Daimler Mk II - 9.00-16 or 9.25-16 as above Daimler Scout Car - 7.00-18 This is 7" wide tyre on an 18" diameter rim. Forgot to say there was no standard specification for Daimler Scout car and different roofs were fitted , early ones had four wheel steering and two steering wheels, later changed to two wheel steering, single steering wheel, so you haven't even got a standard weight for the vehicle. At the time of the D day landings some Dingos had wading screen to allow them to wade to a depth of 10 feet.
  19. This is the internal diameter of the tyre, which is the same as the diameter of the rim onto which it fits. (this diameter does not include the upstanding flange alongside the bead of the tyre, it is the diameter of the well into which the tyre fits.) It does not have any relationship to outside diameter of the tyre. This gives you further problems. A British 14.00x 20 Bar grip tyre is 14" wide , fits on a 20" diameter rim and is roughly 48" outside diameter. The U.S. made version of a 14.00 x 20 is also 14" wide, fits on a 20" rim but is nearer 50" outside diameter. A British road pattern 14,00 x 20 is also nearer 50" outside diameter, so there will be big variations in the "length" of a tyre, according to the tread pattern, and in which country it was made.
  20. Spare sandwiches.....food fight!
  21. Well it means you know fairly accurately the width's of the tyres associated with the vehicles. This being the first figure in each case, measured in inches. The Humber MkIV shows it has run flats, so these will have incredibly strong rigid sidewalls, so the length of contact will be shorter than comparable 10.5" wide tyres fitted to 20" diameter rims. The problem you will have is determining the length of thread in contact with the ground, and this, in my opinion really is "how long is a piece of string?" Also 9.25" wide tyres are nearly 3% wider than 9.0" tyres so you will end up with two different ground pressures for some of these vehicles depending on which tyres where on the vehicle at the time. (although there may well be a different length for either width which further muddies the waters....) And seeing that ground pressure varies between front and rear axles you need laden axle weights for these vehicles. I note also your query about Half track. To be technically accurate you cannot work out an exact ground pressure for any tracked vehicle since each road wheel will carry a different weight, the vehicle being nose or tail heavy, and seeing as the track flexes, some road wheels will be further in the ground, and the tracks around that area will have a higher local ground pressure than other areas of the track where the road wheels are carrying less weight. Maybe not overly important, but another piece of string to try and measure. Tank or halftrack ground pressure is an average figure, and even when accelerating the torque tends to lift and lighten the front of the tracks and put a higher ground pressure under the rear of the track. (true also of armoured cars where ground pressure per wheels varies constantly under acceleration and braking.) Good luck in your mission.
  22. But length of tyre depends on tyre pressure and this could have varied widely and length depends upon weight applied so "length" will not be the same for a particular tyre type fitted to one vehicle as the same tyre fitted to another vehicle, which I why I say how long is a piece of string. There is no standard length a given tyre size is going to be. No-one will have accurate information as to the length of a particular tyre type adopts at a certain loading, you will have to find a vehicle and measure it for that vehicle.
  23. String maybe not, but sound like a planimeter might be of use....
  24. Not Army, but RAF, looks like roundel on front to me anyway. Bridge plate on offside, Roundel nearside, Union Flag above roundel? Taken at scene of a 1958 Supermarine Swift undercarriage related mishap at RAF Jever.
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