Do escape lanes work?
in [UK Drivers]
|
From: Phil Bradby on 17 May 2010 13:29 ....the ones on steep downhill runs. Just curious - seems a bit unlikely to me that a few feet of sand could stop a massive lorry hurtling down a 1 in 4. How often do they get used in anger?
From: Mortimer on 17 May 2010 13:55 "Phil Bradby" <nospam(a)nospam.com> wrote in message news:hsrue0$g4m$1(a)speranza.aioe.org... > ...the ones on steep downhill runs. > > Just curious - seems a bit unlikely to me that a few feet of sand could > stop a massive lorry hurtling down a 1 in 4. How often do they get used > in anger? The sand is deep enough for the lorry to sink up to its axles (and maybe beyond this), which apparently is enough to stop the lorry. I've seen furrows in the escape lanes on the A169 Blue Bank (near Whitby) and on the A44 Fish Hilll (near Broadway in the Cotswolds) which suggests that they do get used from time to time.
From: Brimstone on 17 May 2010 14:45 "Phil Bradby" <nospam(a)nospam.com> wrote in message news:hsrue0$g4m$1(a)speranza.aioe.org... > ...the ones on steep downhill runs. > > Just curious - seems a bit unlikely to me that a few feet of sand could > stop a massive lorry hurtling down a 1 in 4. How often do they get used > in anger? There's one on the descent of Swainswick Hill, on the A46 towards Bath. I passed just after a young chap with his mates in the car mistook it for the road and the were scrabbling round trying to work out how to get the car out which was up to its axles. They work because the sand/gravel isn't a solid surface and any vibration causes the material to move around making space for the wheels. I'm sure one of the resident "experts" will be along to slag me off and provide a more technical appraisal soon.
From: Phil Bradby on 17 May 2010 14:50 Brimstone wrote: > "Phil Bradby" <nospam(a)nospam.com> wrote in message > news:hsrue0$g4m$1(a)speranza.aioe.org... >> ...the ones on steep downhill runs. >> >> Just curious - seems a bit unlikely to me that a few feet of sand could >> stop a massive lorry hurtling down a 1 in 4. How often do they get used >> in anger? > > There's one on the descent of Swainswick Hill, on the A46 towards Bath. > I passed just after a young chap with his mates in the car mistook it > for the road and the were scrabbling round trying to work out how to get > the car out which was up to its axles. > > They work because the sand/gravel isn't a solid surface and any > vibration causes the material to move around making space for the > wheels. > > I'm sure one of the resident "experts" will be along to slag me off and > provide a more technical appraisal soon. If they do work and they do stop such a heavy vehicle moving so quickly in such a short space, how could the driver possibly survive the impact? It must be like hitting a brick wall to stop dead in a few feet in those conditions.
From: Brimstone on 17 May 2010 15:00
"Phil Bradby" <nospam(a)nospam.com> wrote in message news:hss34s$r5q$1(a)speranza.aioe.org... > Brimstone wrote: >> "Phil Bradby" <nospam(a)nospam.com> wrote in message >> news:hsrue0$g4m$1(a)speranza.aioe.org... >>> ...the ones on steep downhill runs. >>> >>> Just curious - seems a bit unlikely to me that a few feet of sand could >>> stop a massive lorry hurtling down a 1 in 4. How often do they get used >>> in anger? >> >> There's one on the descent of Swainswick Hill, on the A46 towards Bath. >> I passed just after a young chap with his mates in the car mistook it >> for the road and the were scrabbling round trying to work out how to get >> the car out which was up to its axles. >> >> They work because the sand/gravel isn't a solid surface and any >> vibration causes the material to move around making space for the >> wheels. >> >> I'm sure one of the resident "experts" will be along to slag me off and >> provide a more technical appraisal soon. > > If they do work and they do stop such a heavy vehicle moving so quickly > in such a short space, how could the driver possibly survive the impact? > It must be like hitting a brick wall to stop dead in a few feet in those > conditions. Whilst the rate of deceleration will very rapid, it won't be as quick as you suggest. The driver will also have had time to brace himself. |