PDA

View Full Version : Chains for tie down?



Jon Nelson
06-07-2004, 03:48 PM
Is it acceptable to use chains for tie downs on one end of the car?

I have plenty of room to fit a conventional ratchet strap at the rear, direct from the trailer frame to factory tie-down hooks, but a VERY small amount of space for tie downs at the front.

Is there any problem with using a couple of short lengths of chain and clevises?

Thanks,

Jon

Chris Sawatsky
06-07-2004, 04:16 PM
while what I do typically has very little bearing on the "right" way to do things, I use a chain in the back, hooked onto two tiedown points on the trailer, with the middle attached to the rear center tow hook with a clevis/caribeener thingy

two ratchet straps in the front complete the deal. It's worked great for the past few years.

also, in my first year of towing, I used chains front and rear, one in the back, the same as I am now, and two in the front, using chain tensioners to compress the car's suspension and keep it very tight

nlevine
06-07-2004, 05:37 PM
For my Honda, I had two chains with hooks on the front of the trailer. Drove up on the trailer, hooked the chains to the factory tie-down points (crossed left side of trailer to right tie-down point on the car, etc.) and then used ratchet straps on the rear tie-down points. It's a quick tie-down method and ensures that the car is in the same position every time. Plan to do the same with the new car (BMW), but will be using these cool J-hook thingies that fit the factory tie-down notches in the bottom of the car.

-noam

Quickshoe
06-07-2004, 06:22 PM
Chains would be prefered assuming you have adequate means to make them tight such as racheting binders.

Chains don't have the short life span of straps due to exposure to elements, nor abrassion issues.

When was the last time you saw a big piece of equipment secured with straps?

That being said, I use straps because their strength is more than adequate for my use. They are easy to store, light and they won't scratch the paint.


[This message has been edited by Quickshoe (edited June 07, 2004).]

bill f
06-10-2004, 06:16 PM
On the comparison of straps/chains with heavy equipment, I might add this:

On long haul equipment, chains are used with equipment that have no suspensions. Our race cars are frequently secured to the chassis (which does move up and down), instead of the axles (which don't move up and down). This may introduce an entirely different dynamic to the problem.

My point is this: with the car chassis movement vertically due to the irregularities in the road, the chains will be given instanteous loading when the chassis motion is required to come to a "sudden" stop. Essentially, the motion is allowed to increase, until the chain's length stops it...Suddenly. This is very high loading. Straps allow a more progressive deceleration, which may be less damaging to the strap, than the instant load is to the chain.

Heavy equipment on a trailer, that has no suspension, can have the chains in constant load, and never exceed their ratings. Instaneous loading might exceed the load rating of the chain.

Just a thought.

Good racing.

Bill

mlytle
06-12-2004, 11:57 PM
not to mention the instantaneous loading from chains on the connecting point on the car!

no thanks. i use straps.

marshall

67ITB
06-13-2004, 01:50 AM
I don’t know how this compares, or if its apples and oranges….
But I have loaded many railroad cars with wheeled vehicles weighing over 40 tons and we use chain, and go to the vehicle frame not the axles to limit suspension travel.
I have never seen a chain failure in over 2500 vehicles. And for an additional reference point we use the same chain to hold down 70+ ton track vehicles, again without a single failure.
The same method is used on the boat, and that is a worse ride than ANY road in the country.
But on my car I use cargo straps cause they were cheaper, cleaner & easier for that application.

Matt Bal

Greg Amy
06-13-2004, 10:00 AM
It's not failures of the chains or straps you have to worry about, it's failures of the attaching points on the car or the trailer.

Using chains that don't "give" to tie down a car is the same idea as using chain for seatbelts to tie down a driver: Instantaneous g-loads are, well, instantaneous. By using nylon straps that will stretch it allows those g-loads to be dissipated. Without that you run a real risk of pulling out a chassis tie-down or a trailer tie-down ring. Chains are fine for strapping down lumber, bricks, and forklifts with no suspension, but add in any drift of the load and it can snap back and break something.

Look at the ratings of those straps; you could hang several of your cars form one before failure. The weak point in the tie down system is the points that they attach to, not the straps.

GA

lateapex911
06-13-2004, 01:11 PM
Along the same lines, lets discuss a few combinations using chains.

Lets get feedback on the merits...

- Straps to chassis front and rear.
- Straps to control arms (or axle) at the wheels
- Chains to chassis,
-Chain to control arm in the front, and straps to the control arm odr axle in the rear.

I like the second choice best, the fourth next, and the third choice last.

Thoughts?



------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

apr67
06-13-2004, 02:14 PM
I'm not fond of putting anything to a control arm (but I have done it out of desperiation). They were not made for that type of load in my opinion. To spend $$$'s to get alightment right and then destroy it on the way to the track worries me.

If I want to hold the car down by it's unsprung mass, I would prefer to use wheel nets or whatever they are called.

But thats a pain, so I just use regular straps to the chassis. But I have been looking at chains for the back because I don't have enough distance to use the straps well.

Quickshoe
06-14-2004, 01:56 AM
Originally posted by grega:
Using chains that don't "give" to tie down a car is the same idea as using chain for seatbelts to tie down a driver

Or a HANS instead of an ISAAC http://Forum.ImprovedTouring.com/it/biggrin.gif

I would think that most factory tie down points would be stronger than a strap. Further the rating on the strap you are refering to is probably static.

The hardware rating is probably lower than the strap (as is it in new harnesses).

Maybe the best method of all is to secure the car with straps through the open spokes in your panasports, with abrassion resistant sleeves and then tie the car to the trailer with a semi-slack chain just in case the straps fail. In case of an accident your car might stand a chance of staying on the trailer.


[This message has been edited by Quickshoe (edited June 14, 2004).]

x-ring
06-14-2004, 10:02 AM
I like the idea of chain in the back and straps up front. Why? The most likely case for sudden, excessive, loading on your race car is in the forward direction as in panic braking or an accident. True, you can be rear-ended but it won't load your tie downs as much as the other case.

I worry about this because of an experience I had a couple of years ago where someone pulled into the lane in front of me and then slowed suddenly to make a right turn. Under hard braking the rear straps streched enough to allow the front straps to unhook. When I got off the brakes the car rolled backward, not off the trailer since the rear straps were too short, but far enough to get my attention.

BTW, I also got rid of those 'D' shaped rings that were too big to let the gate snap shut on the hook.



------------------
Ty Till
#16 ITS
Rocky Mountain Division

Dave Hardy
06-14-2004, 03:40 PM
I use a chain in the back to the tow loop under the license plae on my Civic. On the Front I use ratchet straps and cross them.

Whys:
The chain on the back is because in a frontal collision, I don't want my racecar trying to run into me. There should be no shock loading, as the chain already has several hundred pounds of tension in it just from ratcheting the straps.

The straps are in front because they don't need to be as strong and they are easily tensioned. They are crossed to prevent sideways motion of the car on the trailer, much like a diagonal brace on a rollbar.

Other stuff - I tie the car down and ratchet it tight with the e-brake released. That way the brakes are not fighting the straps. After that though, I do pull the ebrake for the trip. In case all else fails and the car does hit the road, I want it to stop eventually. I also leave the car in neutral on the trailer.

[This message has been edited by Dave Hardy (edited June 14, 2004).]

lateapex911
06-14-2004, 08:04 PM
Keep in mind that if a strap breaks when it's crossed, you are in trouble. The car will move sideways, then the strap will be loose because its "longer"....

And I should edit my comments earlier. I meant a chain at the back, not the front in option 4.

But, another thought..on one hand, the conrtol arms and suspension are designed to handle the loads of braking cornering and acceleration..so in one sense, there should be no issue using them for tie downs. But on the other hand, the front control arm is designed to withstand the force of the car pushing forward against the tire contact patch under braking, not the other way around, as it will see in towing....

I doubt if it really matters though, and it's splitting hairs.

------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[This message has been edited by lateapex911 (edited June 14, 2004).]

[This message has been edited by lateapex911 (edited June 14, 2004).]

apr67
06-15-2004, 12:07 AM
Originally posted by lateapex911:
But, another thought..on one hand, the conrtol arms and suspension are designed to handle the loads of braking cornering and acceleration..so in one sense, there should be no issue using them for tie downs. But on the other hand, the front control arm is designed to withstand the force of the car pushing forward against the tire contact patch under braking, not the other way around, as it will see in towing....


When I used to work with used cars we would sometimes tow a dead car around the lot with a rope and a pickup. Once we had a car with one front brake locked. Bent the rear a-arm (FWD car).

Most A-Arms are not designed to have something pull on the center of them. They have very little strength orinted that way.