Stuart Galbraith Posted April 20, 2021 Share Posted April 20, 2021 32 minutes ago, skylancer3441 said: ...same for T-15 HIFV, and front-engine version of BMP-3. I must have missed that one. Link to comment Share on other sites More sharing options...
GJK Posted April 20, 2021 Share Posted April 20, 2021 (edited) On 4/18/2021 at 6:46 AM, Ssnake said: You can just as well hoist it with a steel cable. That being aid, hydraulic systems as such don't take up much space (that's why engineers love them if volume constraints are significant), and if you have a hydraulic system already, laying two pipes to operate the door isn't going to be a significant complication. The main argument against hydraulics is that they are horribly inefficient; about 40% of the energy input dissipate into internal leakage. The main problem with hydraulics in AFVs is the hydraulic fluid burning in the event of the vehicle being hit. I recall this being a particular issue with the turret traverse in M60 spraying the oil from punctured pipes in a mist which then ignited causing a flash fire in the turret when Israeli tanks suffered hits. In some cases, particularly maintenance and engineer variants, hydraulic systems internally are inevitable. The ram for the rear door on the Warrior section variant is well hidden at low level and Challenger ARRV has a separate winch compartment, but I have been in REME Warrior variants where winch and crane hydraulic pumps were a bit more exposed! Best, Greg. Edited April 20, 2021 by GJK Link to comment Share on other sites More sharing options...
Ssnake Posted April 20, 2021 Share Posted April 20, 2021 ...or you build a powerful electrical subsystem and then use servo motors etc. Not quite so low volume as hydraulics, but less of a fire hazard obviously. Link to comment Share on other sites More sharing options...
Wobbly Head Posted April 20, 2021 Share Posted April 20, 2021 (edited) 36 minutes ago, GJK said: The main problem with hydraulics in AFVs is the hydraulic fluid burning in the event of the vehicle being hit. I recall this being a particular issue with the turret traverse in M60 spraying the oil from punctured pipes in a mist which then ignited causing a flash fire in the turret when Israeli tanks suffered hits. In some cases, particularly maintenance and engineer variants, hydraulic systems internally are inevitable. The ram for the rear door on the Warrior section variant is well hidden at low level and Challenger ARRV has a separate winch compartment, but I have been in REME Warrior variants where winch and crane hydraulic pumps were a bit more exposed! Best, Greg. I think the bigger problem is you are looking directly at the clear fuel tank that's mounted on the side wall when sitting in the back seats of the REME warrior variants repair and recovery. This is especially the case when the crew tell you not to look at them just before they drive you cross country as it is very well known for inducing extreme nausea. Edited April 20, 2021 by Wobbly Head Link to comment Share on other sites More sharing options...
GJK Posted April 20, 2021 Share Posted April 20, 2021 1 hour ago, Wobbly Head said: I think the bigger problem is you are looking directly at the clear fuel tank that's mounted on the side wall when sitting in the back seats of the REME warrior variants repair and recovery. This is especially the case when the crew tell you not to look at them just before they drive you cross country as it is very well known for inducing extreme nausea. Diesel doesn't have the same combustion properties as hydraulic oil. Give me motion sickness over flash burns any time! In all Warrior variants the fuel tank is in the centre under the turret or cupola, so no-one has to stare at it. The clear plastic tank was changed to a translucent one around the early/mid 90s (I think) to reduce the motion sickness induced by watching the fuel slosh whilst bouncing around in the back. Best, Greg. Link to comment Share on other sites More sharing options...
Wobbly Head Posted April 21, 2021 Share Posted April 21, 2021 4 hours ago, GJK said: Diesel doesn't have the same combustion properties as hydraulic oil. Give me motion sickness over flash burns any time! In all Warrior variants the fuel tank is in the centre under the turret or cupola, so no-one has to stare at it. The clear plastic tank was changed to a translucent one around the early/mid 90s (I think) to reduce the motion sickness induced by watching the fuel slosh whilst bouncing around in the back. Best, Greg. It didn't work it was still a puke generator. Link to comment Share on other sites More sharing options...
GJK Posted April 21, 2021 Share Posted April 21, 2021 8 hours ago, Wobbly Head said: It didn't work it was still a puke generator. Can't say that matches my experience. Link to comment Share on other sites More sharing options...
bojan Posted April 21, 2021 Share Posted April 21, 2021 Why not non-transparent fuel tank? Link to comment Share on other sites More sharing options...
DKTanker Posted April 21, 2021 Share Posted April 21, 2021 17 hours ago, GJK said: Diesel doesn't have the same combustion properties as hydraulic oil. You might read this to resolve any mythology questions one might have. https://apps.dtic.mil/dtic/tr/fulltext/u2/a212596.pdf And you're right, Diesel doesn't have the same combustion properties as OHT (the hydraulic fluid used with M60s in 1973). DF2 has a minimum flash point of 52C, that of OHT is 82C. For more light reading: https://apps.dtic.mil/dtic/tr/fulltext/u2/a019775.pdf Link to comment Share on other sites More sharing options...
GJK Posted April 21, 2021 Share Posted April 21, 2021 (edited) 17 hours ago, DKTanker said: You might read this to resolve any mythology questions one might have. https://apps.dtic.mil/dtic/tr/fulltext/u2/a212596.pdf And you're right, Diesel doesn't have the same combustion properties as OHT (the hydraulic fluid used with M60s in 1973). DF2 has a minimum flash point of 52C, that of OHT is 82C. For more light reading: https://apps.dtic.mil/dtic/tr/fulltext/u2/a019775.pdf No mythology. My point (badly made I grant you), was diesel leaking from a fuel tank at atmospheric pressure is one thing, but oil escaping from a pressurised system in a confined space with people in close proximity is another. I am well aware from my job that diesel presents a fire hazard contrary to what is often assumed. Only this week I have been reviewing an initial report into an accident where diesel fuel leaked onto hot engine components and caused a fire. Best, Greg. Edited April 22, 2021 by GJK Link to comment Share on other sites More sharing options...
GJK Posted April 22, 2021 Share Posted April 22, 2021 On 4/21/2021 at 12:00 PM, bojan said: Why not non-transparent fuel tank? No idea. I used to sit on an aluminium fuel tank in a Spartan, could easily have used something similar in Warrior. Best, Greg. Link to comment Share on other sites More sharing options...
Stuart Galbraith Posted April 22, 2021 Share Posted April 22, 2021 Probably in case the fuel gauge broke... Link to comment Share on other sites More sharing options...
GJK Posted April 22, 2021 Share Posted April 22, 2021 Ha! May be some truth in that! Link to comment Share on other sites More sharing options...
bojan Posted April 22, 2021 Share Posted April 22, 2021 In that case you leave 5cm wide window in the tank, no need for entire thing to be transparent. Link to comment Share on other sites More sharing options...
Wobbly Head Posted April 22, 2021 Share Posted April 22, 2021 13 minutes ago, bojan said: In that case you leave 5cm wide window in the tank, no need for entire thing to be transparent. Most British AFV's with metal fuel tanks had the fuel in rubber bladders so that wouldn't work. My guess is cost if there is a way to do something the MOD will pick the cheapest. Link to comment Share on other sites More sharing options...
GJK Posted April 22, 2021 Share Posted April 22, 2021 True, the MoD can scrimp with the best government departments. Trouble is the end up saving a penny today to spend a pound tomorrow. I know Scorpion and Scimitar have fuel bladders, but they are not in tanks like Spartan, just a compartment at the rear of the hull. Best, Greg. Link to comment Share on other sites More sharing options...
Adam Peter Posted April 24, 2021 Share Posted April 24, 2021 They can't allow a nausea gap to BMP-1. Link to comment Share on other sites More sharing options...
Stuart Galbraith Posted April 27, 2021 Share Posted April 27, 2021 I suppose its one way of encouraging everyone to dismount.... Link to comment Share on other sites More sharing options...
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