What speed

[Ross]

I believe that the limitation was

based on being able to control the truck and trailer in severe stopping situations. It is easy to build a hitch with high load ratings, but maintaining control of an eight ton trailer with a three ton truck in a panic stopping situation would be pretty dicey.The energy required to stop a vehicle increases as to the square of the speed.So going from forty MPH to sixty MPH increases the stopping energy by 2.25 times.

 

[Big Windy]

Hitch

Ross...I'd say that weight limit was for the hitch not the truck. An F450 could tow three times that weight. Also, GM puts the same hitch on every pick up. It has a max tow weight of 12,000 even thoght the mahority of truck could not pull that much...just cheaper to put the same hitch on all trucks.

 

[Ross]

The point

is not how much you can tow but how much you can safely stop in an emergency.

 

[Echo Gulf]

Braking!

Ross you are right braking distance is a major concern, but one that can easily be overcome with the right equipment. There is no reason that you can't achieve most hi-way speeds, or beyond, safely, while towing a heavy load.  When I designed our boat trailer I purposely went to heavier axles to get the benefit of the larger brake drums that came with them. I have two 8000lb axles with 16inch rims and the corresponding brake drums supporting 9000lbs of boat and trailer. Prior to any road trips I conducted my own tests to prove that I could safely handle the load under any conditions. The trailer brakes and the truck system worked in perfect harmony to provide better than normal stopping abilities under all conditions. Further, I tested stopping power useing just the truck brakes and again with just the trailer brakes. The results were not ideal, but satisfactory enough to be considered safe on the road.  I think that it is necessary to look at a number of factors (ie: brakes, tow vehicle, hitch, etc) to determine the safety of a rig and its abilities on the hi-way. Don't get too fixated on any one area.EG

 

[Pete]

advisory speed limits ? ? ?

Pat where down south are you that there "advisory speed limits"? Are they "advisory" tickets also? driving 80 to 90 mph is not acceptable behavior on any highway and does nothing but endanger everone else on the road. Have a tire blow out at 90 mph towing a trailer and tell me then how safe it was ! It is one thing doing that on a race track where you and the others a taking a acceptable risk (to yourself) but why put all the rest of the public at risk on public highways !

 

[tom b]

Speed limits are advisory?????

Wow...what do the signs say.. The State of Georgia suggests you drive 65. Although if no one is looking you can drive 90. If pulling a trailer, be courteous, don't slow others down. Then I would assume that right arrows and left arrows are only alternative ways to go.. Are Red lights merely a suggestion to stop?? Does the Yield sign indicate that whoever is fastest wins the lane?? And since when does a SCCA course or driving course include driving with a 3000+ anchor in the back. Vehicle dynamics go out the window when your towing and things go wrong.  I applaud the fact that you've not had a mishap so far. Good luck in the future. Imagine what happens when things go wrong at 60 or 65. What do ya think happens when your doin 80 or more... Towing 3000lbs at 80 or 90 really isn't being a responsible driver in any State. Ask any of your drivers training instructors. SCCA or otherwise......Merry Christmas and Happy New Years to all......

 

[Ross]

Energy = Mass times velocity squared

So towing a 6000 pound boat (mass) At forty MPH (velosity)or 59 feet per second squared equals 20.9 million foot pounds of energy.At 60MPH or 88 feet per second squared times 6000 pounds equals 46.5 million foot pounds of energy.At 80 MPH or 117 feet per second squared times 6000 pounds equals 82 million foot pounds of energy.One horse power equals 33000 foot pounds per minute or 550 foot pounds per second. So what all of this means is that the brakes on this towing combination are going to have to absorb all of this energy without failing in order to stop the train. If you have a mile in which to stop you're ok but as the stopping distance gets shorter the energy (read that heat) demand increases. At 80 MPH it will require that the brakes absorb 113 kilowatts of energy. while at 40 MPH the brakes need to absorb only 28 kilowatts hopefully in the same amount of time.

 

[Dennis]

Look at the tractor trailers

Look at the big rigs, which are made to haul heavy loads and what happens to them when they have a highway mishap! All that weight has to go somewhere!

 

[Pat McCartin]

Obviously

I am in inferior human to all of you. Good by, good luck, oh and merry Christmas

 

[Ross]

Pat ,reply # 28

There is still hope for you! Just try not to kill yourself in the mean time.;-)

 

[Dennis]

Every man and woman

Hey, every man and woman is supposed to be equal here. Sometimes we just think a little differently, thats all!!!!!

 

[Tereza]

Leave the fun driving for when the trailer's home

I (and anyone who has ever driven with me) consider myself a "spirited" driver. I have done some amateur racing at Lime Rock, and spent 3 years living in Germany, driving big German cars on the Autobahn, the way they were built to be driven. There, we would "slow down" to about 90 or 100 mph when it was raining.I try to be an extremely aware driver. When I trailer my 360lb boat, I keep it at about 60. There's just too much that can go wrong, with equipment (i.e. bearings, tires), crummy roads, dumb drivers, deer, to push things. I have fun when I drive my Mini, and sure got lots of the fun driving out of my system during those 3 years with the best drivers in the world, so I have no problem lumbering along in the right-hand lane when towing.In fact, I find it rather liberating to have no need for passing every bozo on the road, and to just tool along.Try it - your passengers, and possibly fellow drivers, will thank you!!

 

[Ross]

corrections

This thread... Has degraded it to the name calling the internet is famous for.Quote fromat,UNTIL YOU LIVE IN MY SHOES (FOR ATLEAST A DAY) DON'T JUDGE ME...it's unbecoming and shows your ignorance.When I have an incident that is a violation of law I will pay the price. I accept that. Until now that has not happened. Incidentally Georgia does NOT have a special speed limit for trailering.Each state makes it's own laws and they are DIFFERENT. Because California thinks people can't think for them selves, they set the speed at 55. Others are different. Recently I remember Montana having a speed limit of "Reasonable and Prudent"If you're not a resident of GA, don't comment. As I stated earlier, those of you who have fallen to NAME CALLING are just proving their ignorance. End quote.Pat, I do hope that you are able to contain your anger when you are sharing the highway with hundreds of other people. All that I have posted here concerning towing a heavy load was about the need to be able to control the rig during an emergency stop. The greater the speed of the rig the more difficult it becomes to safely stop in an emergency. I certainly would not want to see anyone maimed because an overly confident driver was unable to avoid a collision.Accident don't "Just Happen" they are caused by someone doing something stupid and someone else not paying attention. Driving with the traffic is the safest speed under most conditions. A man called his wife on his cellphone and she said that he should be extra careful some fool was driving the wrong way on the interstate. And he said "NOT just one there's hundreds of them.

 

[Les Blackwell]

A story to lighten this thread

I have changed the names to protect the guilty and the location. I have a friend who has a C22 which he trailers from race to race. If no races, he heads for the nearest ramp just to sail.One recent day having had a great sail, he dropped the mast, loaded the boat on the trailer and headed for home. The ramp is close to I5 freeway and he had just entered the traffic when his pick up truck broke down. Damn, he didn't have his cell phone and he didn't want to wait for the state patrol to seek help, so he thought he would just go back to his boat and use the VHF that was aboard.So he calls Seattle Coast Guard Group 13 and asks for help. CG returns his call and asks if he need assistance. Yup. Are you wearing your PDF and what is your location? No, I'm not wearing my PDF and my location is Interstate 5 about a half mile from the Everett ramp. CG pauses and then asks, can you give us that location again. Yes, I5 about a half mile from the boating ramp.There is a long pause from the Coast Guard and then the voice responds. Holy smokes, how fast were you going when you hit shore?Hope this lightens the tension on the list.

 

[Pete]

Les...

... just wondering if your friend was cited for the illegal use of a VHF radio? I'm guessing it's illegal to use a VHF in this way in all the 50 states...

 

[patrick]

Pete, now you have done it!

"... just wondering if your friend was cited for the illegal use of a VHF radio? I'm guessing it's illegal to use a VHF in this way in all the 50 states..." Now the CG will have to go back and get the FCC to send this guy a ticket!They did actually fine a boatyard in Seattle (Seaview west?) a few years back for using marine handheld radios to talk to boats being moved around from their own company docks for servicing. That was truely a heinous crime but when the Seattle Harbor Patrol discovered that they (SPD) had never even applied for a license for their shore station, it was ok. I am sure that they were right!

 

[Pat McCartin]

VHF story is great...

We had a guy move is 48' Expensive Ketch here to the lake about 4 years ago. About 6 months after moving here his Epirb went off one day. The CG called the number listed, his mother in law, and asked her what was going on. SHe asked them why, they responded, well the EPIRB is alarming and we show it 300 miles inland.

 

[kendall]

I know

My opinion is that a trailer SHOULD be able to do the speed limit, if not then something is wrong with it either mechanically or by design.  I do agree that in case of heavy loads you should slow it up a bit, but comfortable speed is a personal thing, towing trailers I'm more comfortable at 70, unless it's a large or heavy trailer, then I slow it down a touch because of stopping distance. But a lot of my comfort is because I used to haul mobile homes  Ken.

 

[Nevada City Bob]

55-60

Took my boat along to visit my parents in SoCal this summer (1,150 mi rnd trip) and kept it under 60 the whole way. I felt safe and it handled nicely. Not a good idea to tow something when you're in a hurry. The NTSB does their crash tests at 35mph and you've seen those results. Speeding may be fine if you have the road to yourself, but when there are others on the road that may not have your excellent skills and focus and equipment, slower is better IMHO.