Post by silverdragon on Jan 10, 2018 11:36:30 GMT
In the last programme of the last series, Hawaii 5-0, they dealt with a Semi- on the move, Articulated, cab and trailer.
The truck has people in the back, it needs to be stopped, because estimates say it could drive for up to three days continuously, and it just blew through a road block smashing many cop cars, and afterwards, it has exactly ZERO scratches to the front bumper...
Two main parts to this move...
1st, you can detach the trailer from a MOVING wagon.
2nd, cutting the suzies wont immediately create a mass vacuum loss and dynamite the brakes.
Pt one, from the deck between the cab and trailer, "hero" was seen to reach UNDER the trailer to the 5th wheel and detach the trailer by pulling the pin.
Two minor problems here.
Maybe its different in U$A, but, in UK, that pin is a little more than arms length away from the front of the trailer, and anyway, has to be pulled "sideways", as in towards the driver whilst stood at the side of the vehicle.
You pull it slightly forwards to unlock, and then out towards you to disengage.
And its not that easy.
To dissuade accidental pulling, its rather stiff.
Also. the gap between trailer and cab is not that great, howcome he didnt get his arm mashed by pulling that pin and the trailer dropping?.
Another part, if you were to try to pull that pin on the move, the weight of the trailer pulling on the pin would make it almost impossible to pull...
2nd part of the myth.
Cutting the suzies...
The pipes connecting the air brakes and electrical's between the trailer and the cab are known as suzies. (I have no idea why at this point, I am sure I was told, but that was many years ago?.)
Anyway, as the trailer starts to detach, "Hero" is seen to use his knife to cut the suzies.
On noticing the trailer detcach, "Badguy" driving is then seen to hit the brakes.
the suzies are auto-stop, like some garden hoses use, when you detach, they automatically seal, to prevent leakage.
They are a "Fail safe" system, in that, if you get any sudden loss of brake pressure, you get 100% brakes all the way to a stop.
On cutting the suzies, neither cab or trailer was seen to lock brakes?.. erm?.. hows that again?. the trailer dropped onto its parking legs and tore up some tarmac to stop, the cab went on and braked to a controled stop.
The whole point of this, is if you had just cut the suzies in the first place, the driver would have had NO control over braking at all, and would have stopped anyway.
In that, in many modern cabs, sudden loss of brake pressure would have disabled the throttle control anyway so you couldnt continue driving full thrutch.
So how would I have done it different?.
Well, if you can get between the cab and the trailer and cut the suzues anyway, yer stopping, because thats the way it works, "Fail safe".
All brakes and no throttle on the flat, its not that hard to stop a semi. Brake fade happens on long hills with gravity helping you, not so much on the flat doing a constant 55mph.
Besides, did NO ONE think of getting alongside the trailer reaching out through the passenger window and yanking on the trailer brake?.
If you lock up the brakes on a semi's trailer, its slowing you down no matter what.
Yeah you get brake fade after a while, but its enough to "do something" and force the driver to pull over?.
They mentioned spike strips...
Nah, aint happening.
For a start, truck tyres are different beasts than car tyres, you need a better set of spikes to stop a semi.
Second, by the time you got them, get another semi- or two ahead to slow down and create a rolling road block?.
So, unless USA trailers are built different and you CAN detach the trailer from the front of the trailer...
[Edit...]
BTW, just to note, "shunters", or Yard dogs as you call them, there are some cab units built to move trailers around a yard that have different pin locks that can be accessed from the can unit through a back door. This cab unit was not one of them.
The truck has people in the back, it needs to be stopped, because estimates say it could drive for up to three days continuously, and it just blew through a road block smashing many cop cars, and afterwards, it has exactly ZERO scratches to the front bumper...
Two main parts to this move...
1st, you can detach the trailer from a MOVING wagon.
2nd, cutting the suzies wont immediately create a mass vacuum loss and dynamite the brakes.
Pt one, from the deck between the cab and trailer, "hero" was seen to reach UNDER the trailer to the 5th wheel and detach the trailer by pulling the pin.
Two minor problems here.
Maybe its different in U$A, but, in UK, that pin is a little more than arms length away from the front of the trailer, and anyway, has to be pulled "sideways", as in towards the driver whilst stood at the side of the vehicle.
You pull it slightly forwards to unlock, and then out towards you to disengage.
And its not that easy.
To dissuade accidental pulling, its rather stiff.
Also. the gap between trailer and cab is not that great, howcome he didnt get his arm mashed by pulling that pin and the trailer dropping?.
Another part, if you were to try to pull that pin on the move, the weight of the trailer pulling on the pin would make it almost impossible to pull...
2nd part of the myth.
Cutting the suzies...
The pipes connecting the air brakes and electrical's between the trailer and the cab are known as suzies. (I have no idea why at this point, I am sure I was told, but that was many years ago?.)
Anyway, as the trailer starts to detach, "Hero" is seen to use his knife to cut the suzies.
On noticing the trailer detcach, "Badguy" driving is then seen to hit the brakes.
the suzies are auto-stop, like some garden hoses use, when you detach, they automatically seal, to prevent leakage.
They are a "Fail safe" system, in that, if you get any sudden loss of brake pressure, you get 100% brakes all the way to a stop.
On cutting the suzies, neither cab or trailer was seen to lock brakes?.. erm?.. hows that again?. the trailer dropped onto its parking legs and tore up some tarmac to stop, the cab went on and braked to a controled stop.
The whole point of this, is if you had just cut the suzies in the first place, the driver would have had NO control over braking at all, and would have stopped anyway.
In that, in many modern cabs, sudden loss of brake pressure would have disabled the throttle control anyway so you couldnt continue driving full thrutch.
So how would I have done it different?.
Well, if you can get between the cab and the trailer and cut the suzues anyway, yer stopping, because thats the way it works, "Fail safe".
All brakes and no throttle on the flat, its not that hard to stop a semi. Brake fade happens on long hills with gravity helping you, not so much on the flat doing a constant 55mph.
Besides, did NO ONE think of getting alongside the trailer reaching out through the passenger window and yanking on the trailer brake?.
If you lock up the brakes on a semi's trailer, its slowing you down no matter what.
Yeah you get brake fade after a while, but its enough to "do something" and force the driver to pull over?.
They mentioned spike strips...
Nah, aint happening.
For a start, truck tyres are different beasts than car tyres, you need a better set of spikes to stop a semi.
Second, by the time you got them, get another semi- or two ahead to slow down and create a rolling road block?.
So, unless USA trailers are built different and you CAN detach the trailer from the front of the trailer...
[Edit...]
BTW, just to note, "shunters", or Yard dogs as you call them, there are some cab units built to move trailers around a yard that have different pin locks that can be accessed from the can unit through a back door. This cab unit was not one of them.
