Tandem-axle trailers with no springs

Tedd

.
Jul 25, 2013
746
TES 246 Versus near Vancouver, BC
I was at the boat launch the other day, looking at some tandem-axle trailers. I was surprised to see that none of them had springs. I worry about the ride my trailer is giving my boat even though it has fairly soft leaf springs. I would really worry if it had no springs at all. Can anyone with such a trailer enlighten me about how the boat is kept happy? Is compliance built into the bunks? Do you run low tire pressures? Or do you not worry about it?

Some background: I'm a mechanical engineer with experience in shock and vibration testing and vehicle dynamics. So, no need to explain the intricacies of road shock loads. But it's possible that my background has made me more obsessed with such issues than the average person.
 
Dec 2, 2003
751
Hunter 260 winnipeg, Manitoba
Could they have been intended as yard trailers? For boat storage and movement over short distances at limited speeds?
 
Jun 8, 2004
10,049
-na -NA Anywhere USA
A picture would have been helpful. Could have been yard trailers or ones with torsion if no leaf springs. As for low pressure in tires is dangerous as you should inflate to recommend tire pressure. What boats were in the trailers you saw
 

Tedd

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Jul 25, 2013
746
TES 246 Versus near Vancouver, BC
Yeah, I should have taken a picture, but I wasn't thinking about posting the question, at the time. There were two trailers, both probably for power boats, although I can't be sure because the boats weren't on them. But there aren't many sailboats that launch at that particular site. The axles looked like they were bolted straight to the frame with u-bolts. I've seen that on trailers before, but only smaller ones.
 

Tedd

.
Jul 25, 2013
746
TES 246 Versus near Vancouver, BC
Could they have been intended as yard trailers? For boat storage and movement over short distances at limited speeds?
It wasn't the kind of launch where boats are stored. But there is a marina with boat storage right near by, so it's possible they came from there. I hadn't thought of that. I suppose if you're just moving boats around a yard it wouldn't be worth the expense and complexity of a spring system.
 
May 24, 2004
7,131
CC 30 South Florida
Low inflated tires generate heat and handling problems and should not be used to soften a ride. Years ago some car manufacturer got in trouble for that.
 
Feb 1, 2014
82
Watkins 27 North East, MD
Up to 14x70 schoolroom/office trailers have as many as 7 axles, none sprung. No springs is one less thing to worry about breaking. ;)
 

Tedd

.
Jul 25, 2013
746
TES 246 Versus near Vancouver, BC
Low inflated tires generate heat and handling problems and should not be used to soften a ride. Years ago some car manufacturer got in trouble for that.
There's an ETRTO standard for that. So long as you stay within the guidelines of that standard you won't have a problem.
 
Jun 8, 2004
10,049
-na -NA Anywhere USA
Always follow the load range on each tire times the number of tires. Include the weight of boat trailer and gear. Inflate the tires recommended as seen on the sidewall. Allow 10% of weight to be on the tongue of the trailer to keep better control
Never under inflate because if you do, not only you will feel it but the tire’s will heat up to the point and blow which could cause an accident