In the USA you almost never see semi trailers with wheels that steer. But in Europe and Australia you see them all over. A late friend of mine helped engineer & patent a semi trailer in the late 60s. The rear of the two axles on it steered with the help of a long rod that attached to the tractor next to the hitch. They signed a contract with a large semi trailer manufacturing company to manufacture them under liscence. They had the prototype trailer used in tests hauling freight around the country. One of the tire companies had a part in the testing. One of the last reports was of the noticeably increased tread life on this trailer. Shortly after that he got the call from the trailer manufacturer that they were cancelling the contract and would not make any trailers for them under their patent. My guess is the tire company didn't want sales to go down and pressured the trailer manufacturer to cancel the contract,,, and that happened. If there is one thing that semi trailers could use when in urban traffic its axles that could counter steer when taking sharp turns.
Wouldn't that be a sight,,,, a conventional semi tractor pulling a 60' trailer trying to make a right turn at the intersection of two "two lane roads",,,, and there is a young driver in his way in a car intensely talking to someone on her cell phone not know what to do or even able to realize that she needs to take some action.
Modeling the "Fargo Area Rapid Transit" in O scale 3 rail.
Boyd If there is one thing that semi trailers could use when in urban traffic its axles that could counter steer when taking sharp turns.
If there is one thing that semi trailers could use when in urban traffic its axles that could counter steer when taking sharp turns.
Isn't that what essentially modern fire ladder trucks do with some one in back to steer?? Tree do you know to what length some of those monsters are built?
Sam, thanks for that compliment. I've had the privilege of working with some really talented drivers - most aren't reluctant to tell you that anyway, right ? - who by word and deed demonstrated how it should be done, and told me how it shouldn't. So it's maybe easier for me to observe critically when standing on a street corner.
The Wikipedia "Road Train" article that I referenced above - http://en.wikipedia.org/wiki/Road_train# - does contain several mentions of partially steerable axles in the History, B-Double, and C-Train / C-dolly sections.
An interesting discussion of the Converter or C-dollies and experiences with them from a 3-year field study by the University of Michigan's Transportation Research Institute is on this webpage:
http://www.itec-inc.com/dolly/documnts.html
- Paul North.
Paul North posted:
"...An interesting discussion of the Converter or C-dollies and experiences with them from a 3-year field study by the University of Michigan's Transportation Research Institute is on this webpage:.." [and linked below]
Thanks for posting that link from U of M. Tech Center!
During the driving part of my career in the industry, I had some exposure to pulling combinations of trailers in varied conditions. Mostly the converter dollys I experienced were of the A-type( pintle hook with dolly and single point attachment to the leading unit). Prior to the 21century, A dollys predominated. The only C dolly use I observed were those used by the Batesville Casket Co. of Batesville, In. At that time their company drivers used tandem trailers for delivery of their products. Normally, the rear trailer would have been dropped to make a delivery out of the forward trailer in the comination. With the C dolly configuration, their drivers has a larger measure of control in the placement of the rear trailer in confined spaces that they made deliveries in. It was amazing to watch one of their C converter(double pintle hooks) back a unit up, and around to make a 'spot'. The closest thing to the manoverability of the C-dollly operation was the Canadian B-Train configuration IMHO.
I suspect that the main drawback to the wider use of the C-dolly in the day-to-day operations of the Industry comes down to the factor of Cost and Risk Management.
Mechanically more complicated the C-dolly required a more frequent maintenance cycle due to the addition of self steer, and ABS in the rugged environment they are used in. Not to mention that the heavier dolly (and possibly equipped with a second axle, would make the ground manovering by a single individual problematic. They are dropped in unprotected locations, and sometimes on un-paved lots. A single individual pushing one around to make a hook between two trailer has his work cut out for him.
I hate to be negative, but I would say if there were any advantage to the use of C-dollys over the ubiquitous A-dolly. A cost conscious and concerned employer would take them on in a heart beat.
The A-dollys in use today are constructed very simply, and are comparitively light. A tandem axle C-dolly is a beast to manover in the best of conditions. Those conditions are seldom the case in the real world. Risk of injury in these operations is always present in the real word use, and seldom is a second individual provided to help with the operation; it is mostly a case of random drivers teaming up to get both men's task completed.
Currently, the predominant trailer in the Less than Truckload [LTL] sector is the short trailer (28ft Pup-style). With longer straight floor trailer in a variety of lengths. The Truck Load [TL] (for hire) sector has pretty much standardized on the 53 foot configuration, and equipped as needed by the users.Dry, Reefer,Container, etc.
Going to a longer trailer requires a re-engineering of the longer unit, not to mention the pit-falls of the 'learning curve' of not only the drivers, but the folks that load the trailers, as well. That whole process, and the learning curve become practically stated, 'a female puppy dog'. The possibility of that whole dog, and pony show happening, makes me glad I am retired.
blue streak 1 Boyd: If there is one thing that semi trailers could use when in urban traffic its axles that could counter steer when taking sharp turns. Isn't that what essentially modern fire ladder trucks do with some one in back to steer?? Tree do you know to what length some of those monsters are built?
Boyd: If there is one thing that semi trailers could use when in urban traffic its axles that could counter steer when taking sharp turns.
not to get too off topic but you are rfferring to "Tractor drawn Aerials" or, as they used to be known "tiller ladders"..That type of apparatus requires a firefighter (the "tillerman") who rides in an operator's station at the back of the vehicle equipped with a wheel to steer the rear axle. That type of ladder truck is actually less common nowadays then it was in years past and is mostly employed in heavily built up areas with narrow streets and tight turns..
Not a very applicable system for afreight hauling semi truck as you would need a rear driver!
There are examples of long vehicles with steerable axles that are controlled by the main steering wheel. Many modern hydraulic cranes have that feature..it is much more expensive to own and operate than a conventional semi trailer..
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
There is no need for a 2nd driver if you want steering axles on a semi trailer.
Boyd Wouldn't that be a sight,,,, a conventional semi tractor pulling a 60' trailer trying to make a right turn at the intersection of two "two lane roads",,,, and there is a young driver in his way in a car intensely talking to someone on her cell phone not know what to do or even able to realize that she needs to take some action.
It happens now with the 53-footers. In that case, I either wait for the offending lanes to clear, or just go ahead and start the turn. Usually when they see my tandems heading for their front end, they get the idea and give me some room.
I will agree with the "steering wheel holders", training is a touch on the lax side. I have watched drivers take a long time to try to get in a spot, only to either give up and try to find another, or wreck one or both trucks on either side of the hole he is trying to get in.....
Randy Vos
"Ever have one of those days where you couldn't hit the ground with your hat??" - Waylon Jennings
"May the Lord take a liking to you and blow you up, real good" - SCTV
Reminds me of a comment that one of the contractors for our house made while watching 2 fellows unload his big John Deere tracked excavator from a "low-boy", and then 'back-and-fill' it to turn around and leave, with much shouting and gesturing as part of the process:
"Takes both of them to drive that rig, too - 1 to steer, and 1 to shift . . . "
Randy Vos, said:
"...It happens now with the 53-footers. In that case, I either wait for the offending lanes to clear, or just go ahead and start the turn. Usually when they see my tandems heading for their front end, they get the idea and give me some room.
I will agree with the "steering wheel holders", training is a touch on the lax side. I have watched drivers take a long time to try to get in a spot, only to either give up and try to find another, or wreck one or both trucks on either side of the hole he is trying to get in...."...
And Paul North, said:
"...Reminds me of a comment that one of the contractors for our house made while watching 2 fellows unload his big John Deere tracked excavator from a "low-boy", and then 'back-and-fill' it to turn around and leave, with much shouting and gesturing as part of the process:
Got my first Chauffeur's License ( USMC) in 1961 and believe me, things have not changed much, if any. Ironically, Truck Stops, and Loading Docks were/ are almost as dangerous an environment for a big truck as trying to make turns in amongst the 4 wheelers in city traffic.
The average city driver is like a rat looking for a hole when a big truck is around. The auto driver will see an opening along side a big truck, whose driver is attempting a right turn ( very probably a virtual zero visibility for the car along the trucks right side) and the auto drive will squeeze in, then be shocked when they get 'trapped' against the curb. The one true fact seems to be that the car getting trapped will invariably be a luxury model of what ever brand the car is and more than likely, very new.
Almost always the trucking company's insurance carrier will pay--The know that if it were to go to trial the trucker will be the one paying the bill for damages and anything else the attorney can throw on the pile. It is cheaper for the large company to take the loss and move on--always the cheaper way ( more than likely, the railroads will do the same where smaller claims are pending--lawyers and their fees get really expensive in a big case.
Frequenting a Wal Mart Supercenter several times a week I wonder if they have considered this size.56',60'.How much food/merchandise will WM be able to fit on these trailers.
I remember when as a kid I was watching a crew dig up a cesspool in our backyard using standard spades. I suggested using a bigger shovel like the coal shovel that was common then. The crew boss said that actually it would not be a good idea as the workers would actually slow down for various reasons and it would actually take longer...the shovel full was too heavy, more time between digs, more "breaks: to catch breath, etc...no, he said the littl shovel worked just fine.
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Then they will get into the less than-trailer-load problem and start telling customers that they have to fill the whole trailer or use alternate trucking services.
Could Railroads then come back with 20' and 40' container services?
Andrew
Watch my videos on-line at https://www.youtube.com/user/AndrewNeilFalconer
It says at the top the trucking industry wants heavier ,longer trucks. I don't think that's true. If you can call Walmart part of the trucking industry it might be true. It is more like the shipper wants things heavier. Walmart has it's own trucks and would like to load them like box cars and save on shipping.
Trucking industry will not gain anything from this. Look at the money and see who will gain the most. Walmart and others like grocery companies and others like them.
blue streak 1Isn't that what essentially modern fire ladder trucks do with some one in back to steer?? Tree do you know to what length some of those monsters are built?
Hadn't checked this thread for a while...
One tillered aerial I checked had an overall length of 58', with the trailer running not quite 40' long from the tractor axle. I would submit that to be a typical length, since there are practical limits as to how long each fly section of the ladder can be (a 100' ladder will usually be four sections).
Such apparatus are typically single axle on the trailer, so tire wear isn't the issue. It's all about maneuverability. While a manually steered rear axle on a semitrailer might have some maneuverability value in urban/frequent delivery application, over-the-road it would just be a maintenance headache - never mind the second "driver."
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
Sorry but as a Former OTR driver that was there when this Freaking push came up in the Late 90's I can tell you this for sure the Answer was the Same then. It is NOT the Drivers that want it or the Smaller Carriers it is the MEGA Carriers the ones with the Names like JB Hunt Swift Scheinder Maverick CR England Central Referigarated Knight. Why because they could knock out most of the Smaller carriers by being able to go to the Larger stuff faster. However if you think the Drivers that haul it are going to be better paid you have to be Higher than some of the people in CA IL and NY that think Democrats did not remove 500 Billion in Medicare as part of Obamas Healthcare Law.
Now getting back on topic Rates now are the same as they were roughly back when the ICC controlled things when weights were stopped at 73280 and lengths were restricted yet the carriers and Shippers pushed forHeavier and longer trailers frist it was 45 footers then 48 now 53 footers. Weights went to 80K and they never rebuilt the Infastructure to hold us out east. NYC's Hunt point can not hold 53 foot reefers and the Conventials that pull them it was designed for 40 footers with Cabovers. There are spots on the West Coast that are just as Bad. Truckstops are the same way and so are rest areas. Yet the ATA which has not Represented the Trucking Industrty for over 30 years since it was deregulated.
I watched a rig carrying a turbine blade that was probably 100" long, maneuver around a T intersection over in Nebraska. The steerable trailer bogie was activated by an RF transmitter. Upon completion of the turn, the guy in the chase PU verified that the bogie was locked in place for the next leg of the journey. I have watched similar trucks carrying bridge segments activate the bogie from the cab when exiting the interstate.
Another question: When the first trailer in a "B-train" is backed up to a dock, is the dock fitted with an extra-long dock plate that spans the distance between the trailer door and the dock?
Johnny,
The simple answer is that very few "B Train" combinations are of a van configuration. Most B Trains are flat beds, that rarely see a loading dock, tanks, curtain vans and chip trucks.
The rare B train van configuration often has the trailer axles slideable, which is common in standard trailer types for weight distribution, and meeting bridge length ( king pin to trailer axle, NOT hwy bridge) requirements/restrictions. with sliding axles, the axles can slide and tuck the rear fifth wheel plate under the trailer, and be docked like any other trailer.
The B Train chip trucks I believe place a cover over the fifth wheel plate when dumping the front trailer, but I have not watched B Train chips dump, just an educated guess, but I have seen plenty of B Train chip trucks out here on the West Coast.
THE #1 way to improve trucking safety in particular, and Highway safety in general, is to improve the driving habits and skills of the typical automobile driver. That would do more to improve safety than any rule or regulation that could be imposed on the trucking industry.
Doug
23 year, 2,000,000+ mile veteran moving freight from A to B
May your flanges always stay BETWEEN the rails
challenger3980 Reply More Another question: When the first trailer in a "B-train" is backed up to a dock, is the dock fitted with an extra-long dock plate that spans the distance between the trailer door and the dock? Johnny, The simple answer is that very few "B Train" combinations are of a van configuration. Most B Trains are flat beds, that rarely see a loading dock, tanks, curtain vans and chip trucks. The rare B train van configuration often has the trailer axles slideable, which is common in standard trailer types for weight distribution, and meeting bridge length ( king pin to trailer axle, NOT hwy bridge) requirements/restrictions. with sliding axles, the axles can slide and tuck the rear fifth wheel plate under the trailer, and be docked like any other trailer. The B Train chip trucks I believe place a cover over the fifth wheel plate when dumping the front trailer, but I have not watched B Train chips dump, just an educated guess, but I have seen plenty of B Train chip trucks out here on the West Coast. THE #1 way to improve trucking safety in particular, and Highway safety in general, is to improve the driving habits and skills of the typical automobile driver. That would do more to improve safety than any rule or regulation that could be imposed on the trucking industry. Doug 23 year, 2,000,000+ mile veteran moving freight from A to B
As to the maneuverabilty of long trailers, I doubt that many motorists remember, if they ever knew, that it is not as easy to turn a tight corner with one of those as it is with a small car. I am not sure how much knowledge is imparted to most motorists by the notices on the rear of many vans, showing that they CANNOT turn as tightly as a Smart Car can.
Johnny
Traveling I-95 I have seen quite a number of over-length concrete beams being transported using a 'tiller bogie' on the rear of the beam. The 'driver' of the tiller has a seat, windscreen and steering wheel....the tillerman is exposed to the elements. Quite a sight to be passing on 40 degree rainy days.....I don't envy the tillermans job on those rigs one iota.
carnej1 blue streak 1: Boyd: If there is one thing that semi trailers could use when in urban traffic its axles that could counter steer when taking sharp turns. Isn't that what essentially modern fire ladder trucks do with some one in back to steer?? Tree do you know to what length some of those monsters are built? not to get too off topic but you are rfferring to "Tractor drawn Aerials" or, as they used to be known "tiller ladders"..That type of apparatus requires a firefighter (the "tillerman") who rides in an operator's station at the back of the vehicle equipped with a wheel to steer the rear axle. That type of ladder truck is actually less common nowadays then it was in years past and is mostly employed in heavily built up areas with narrow streets and tight turns.. Not a very applicable system for afreight hauling semi truck as you would need a rear driver! There are examples of long vehicles with steerable axles that are controlled by the main steering wheel. Many modern hydraulic cranes have that feature..it is much more expensive to own and operate than a conventional semi trailer..
blue streak 1: Boyd: If there is one thing that semi trailers could use when in urban traffic its axles that could counter steer when taking sharp turns. Isn't that what essentially modern fire ladder trucks do with some one in back to steer?? Tree do you know to what length some of those monsters are built?
Never too old to have a happy childhood!
Either I-81 or I-40 down near Knoxville, TN a few years ago, also big concrete beams in transit, the 'tillerman" was in a little cab down in front of and between the wheels of the lead axles of the trailing bogie, just a few inches above the road. Reminded me of the ball-turret gunner in a World War II bomber such as the B-17's - not an enviable position, I'm sure.
The benefits and to whom of longer, heavier trailers must be weighed against the negatives.
C&NW, CA&E, MILW, CGW and IC fan
I think the tillerman is a thing of the past. This youtube explains steerable trailer axles.http://www.youtube.com/watch?v=RulwLn0kthU
Jim
Y6bs evergreen in my mind
Finally, two drivers ran into the sign that the Wyoming Highway Patrol put up at Ranchester, Wyo., warning people about the interstate closure in Montana.
“People apparently can’t see ‘road closed’ signs in red and white with flashing lights,” said Highway Patrol Capt. Carl Clements in Sheridan
That is from an article discussing flooding in Montana, just reafirms my statement about the #1 way to improve trucking and highway safety, is to focus on the driving habits and skills of the average motorist.
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