Where to attach the Breakaway Cable

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On a heavy trailer, I would be surprised to see electric brakes fully lock up on dry pavement. I do believe they would lay a patch of rubber down while still turning somewhat slower than roadspeed. I also think dry drum brakes actually can initially grab more because of superior surface contact area over that of discs. Drums just don't work well under sustained moderate braking (ex: downhill) because of hot liner material gassing, which causes fade. Discs cool better, their prime advantage.

A bit of trivia:
I used to work on a railroad, and our rail-car brakes could occasionally lock a wheel if empty. Steel wheels, on steel track, have less traction than rubber on asphalt. The situation was common enough that we were forbidden to use too much braking, especially an emergency air dump, unless we had a good reason. Some light-weight aluminum coal hopper cars even had a load-sensing device that purposely reduced braking when unloaded.

Early locomotives (and cars) had cast iron shoes which could lock up at slow speeds, but became marginal at high speeds, making downhills chancy. Later locomotives had non-fading composition shoes and the max brake settings alone seemed unable to lock them, even when warm (the trade-off for non-fading was the brakes absolutely had to be warmed about 15 seconds to start fully working). However the later dynamic braking occasionally skids a wheel and newer locomotives can still be frequently heard to have flats spots which hammer loud enough to hear for some distance (and can be felt in the cab).

Modern locomotive air brakes and dynamic braking have a complicated computer control to balance total braking effort and it doesn't always work perfectly to this day yet. Locomotive and train air brakes are mostly separate, with separate air controls.

Wes
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I personally don't buy you claims that you can make your brakes lock up when you want them to, but neither of us can prove any claims one way or another. Such claims for trailers at speeds much above say 20mph and loaded fairly heavy just doesn't pass my personal smell test.

Your a person with a over rated opinion of yourself and can't stand it if some one has different experience or does it different than you.

Just because you don't have the experience necessary to get the full benefit of your trailers electric brakes doesn't mean others don't.

JIMNLIN wrote:
Having a owned and operated a multitude of different kind of trailers from small 7k enclosed trailers to 22k tandem dual GN equipment trailers along with a TT and three 5th wheel trailers I made sure the brakes (all electric) on each and every trailer could lock up........ when I wanted them to.

Then you must know more than the Brake/Axle Engineers at companies such as Dexter that at least folks like me have to consider the experts. Also, you must have some sort of Pixie/Magic dust to get more braking power out of electric based brakes. There is only so much power that that sliding magnet can exert (3A by design) on the brake shoes unlike the much higher and less limited force you can get from a typical hydraulic braking system.

I personally don't buy you claims that you can make your brakes lock up when you want them to, but neither of us can prove any claims one way or another. Such claims for trailers at speeds much above say 20mph and loaded fairly heavy just doesn't pass my personal smell test.

Larry

Larry

Having a owned and operated a multitude of different kind of trailers from small 7k enclosed trailers to 22k tandem dual GN equipment trailers along with a TT and three 5th wheel trailers I made sure the brakes (all electric) on each and every trailer could lock up........ when I wanted them to.

Having been through and involved with more than one trailer disconnect when I was on the road I sure don't want the trailers brakes coming on just 'cause the trailer jumped the ball or any other circumstances. BTDT.
I want to do all the trailer braking at all times that fits a dry/wet/gravel road or snow pack road condition.

I connect all my brake away cables to a point that will not separate from the truck. No I don't use S hooks without a safety clip.

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Larry, Ron,

Thanks again, for the knowledgeable replies.

Wes
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I replace one of my tag bolts w/ a 10-24 stainless "EYE" bolt
and attach to it.

Ron Gratz wrote:

LarryJM wrote:
IMO you have correctly assessed the overall situation and one comment I have is that I often see this concern over "locking" the TT brakes up. First off on normal pavement and with fairly heavy TT I don't think it's possible to really "lock up" these electric brakes.---

At least one trailer brake manufacturer tends to agree.

According to Dexter Axle:

On an unloaded trailer, you may be able to lock up your brakes if your electric brake controller is supplying full amperage to the brakes.
When loaded to capacity, you may not be able to lock your brakes as electric brakes are designed to slow the trailer at a controlled rate, and not designed to lock up the wheels on a fully loaded trailer.

Ron

I know the only time I have ever been able to get my brakes to "lock up" is at speeds under 10mph in CGs on gravel. My unique brake controller allows me to vary from 0 to 12Amps completely independent of my TV brakes using my foot only and I have an amp meter permanently installed to measure the exact current going to the brakes.

Larry

I attach it to the place on the hitch where my safety chains go. I use a hardware store style caribiner clip.... not the cheap aluminum ones you find on the front counter in a tub.

LarryJM wrote:
IMO you have correctly assessed the overall situation and one comment I have is that I often see this concern over "locking" the TT brakes up. First off on normal pavement and with fairly heavy TT I don't think it's possible to really "lock up" these electric brakes.---

At least one trailer brake manufacturer tends to agree.

According to Dexter Axle:

On an unloaded trailer, you may be able to lock up your brakes if your electric brake controller is supplying full amperage to the brakes.
When loaded to capacity, you may not be able to lock your brakes as electric brakes are designed to slow the trailer at a controlled rate, and not designed to lock up the wheels on a fully loaded trailer.

Ron

Wes Tausend wrote:
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I learned, from Ron Gratz's post, that the TT brakes should engage before the chains tighten, so it made me think. Ron wouldn't have posted that if he doubted it's logic or correctness. I'm not presently sure how long my stiffly coiled lanyard actually is, nor what tension will release it, so I have some work to do.

My earlier thought was that I didn't want the brakes to lock up prematurely and jerk the chains any more than necessary, but then that is still better than the likely knee-jerk reaction of applying TV brakes and having the TT ram the rear, possibly to one side. Ramming/lifting the rear, and spinning a pursued vehicle out of control, is the preferred method for law enforcement to disable steering control on a perps vehicle, if that drastic measure becomes necessary.

I think the most likely loss of an RV TT hitch may occur because the operator forgets to put the hitch pin in... or a cruel vandal removes it. I try to remember to look under there each time before I move, but don't always do it. A loose receiver will surely stay in until some later, inopportune moment.

Wes
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IMO you have correctly assessed the overall situation and one comment I have is that I often see this concern over "locking" the TT brakes up. First off on normal pavement and with fairly heavy TT I don't think it's possible to really "lock up" these electric brakes. They are A LOT DIFFERENT than hydraulic cylinder activated brakes. That sliding magnet just isn't strong enough to put that sort of pressure on the brake pads and even if it were possible to "LOCK UP" the TT brakes my answer is "SO WHAT" let'm skid for that few hundred yards till your speed is down to a manageable level. If you have crossed your chains the TT should be pulled in a straight line behind you anyway and ruining a tire or two is going to be the least of your worries, etc.

Finally, in a real disconnect scenario things are going to move SO QUICK and be over in such short order than believing that anyone is going to have any time what-so-ever to do anything other than "HOLD ON FOR DEAR LIFE" and try and keep the TV straight and on the pavement is fool hardy to say the least.

Larry