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View Full Version : Guard Rails - please explain


Michelle
24th Jul 2005, 13:48
Central Vic has been the site of a lot of road works lately. Spefically the Calder highway.
What has been confusing me is the guard rail types that are to be seen along its length.

Traditionally guard rails were made of short posts with some curved alloy side;
A type of rigid guard rail.
But with this new road we're seeing an awful lot of wire rope barriers. About three heavy wire cables inserted into slotted p;osts and capped.
Using physics ideas I can see how they would be better upon impact (the deceleration to zero is much reduced and so the force of impact on passengers is lessened.rather like air bags function really). But my partner (motorcyclist) is mortified by them...reckons he'll get decapitated if he hits them
(personally I think motorcyclists are screwed if they hit any road barrier, rigid or wire rope...)
Now I assumed that these were the 'modern' standard, and that all the road barriers wouldbe built this way but along this stretch of road they alternate! THeres some of the older t ypes, some wire barriers...no method to the madness (and in most cases..these arent protecting cars from any particular areas such as dropoffs or other dangers..theyr'e on nice flat straight stretches).
Even the rope barriers arent consistant. Their spacing varies wildly...have the road engineers gone nuts or...?

swag298
24th Jul 2005, 13:51
They do the same here too.

swag

Michelle
24th Jul 2005, 13:55
I was reading up and it is said the wire ones are often used where there is limited space - however upon impact they give more and therefore require more space behind them to be effective...
They just seem damn dodgy to me...and the fact that the builders cant make up their minds which to use...

TonyT
25th Jul 2005, 11:04
They are not like by motorcyclists (like me), but maybe "give" more when impacted by a car.

El Stiemo
25th Jul 2005, 12:43
They do the same here too.

swag

Seems that there is an international conspiracy for this... We also have the rigids and the wire - type with no clear reason for one or the other at a certain point and no, I really would not want to slide into them (any type) whilst on a bike - or rather whilst not on the bike any more.

OzRR
14th Aug 2005, 01:22
But you'll notice the one's on the calder have trees behind them. Or coppers on the Pukka exit!! Ive never seen the use or purpose of these over the rigid ones, except maybe they had too much cash and thought.. hey.. lets make another barrier that's going to cost heaps to replace!

Oh.. that and the fact that if you happened to go a bit too close, instead of bouncing off them, you shred the whole side of your vehicle against it!!

redbak
21st Aug 2005, 00:58
Maybe a senior Politician owns the wire rope mill ..... :shakehead

Davo