This is an incredible feat of parking skills
https://www.youtube.com/watch?v=98XeWQmbW4I
Not An Inch to Spare
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Not An Inch to Spare
Last edited by yogi on 14 Oct 2019, 19:39, edited 1 time in total.
Re: Not An Inxh to Spare
Wow, I'm surprised he managed to get that car in that spot at all.
Amazing!
I've had to get out of spots where folks pulled up tight against me like that, and it took forever to get out.
Amazing!
I've had to get out of spots where folks pulled up tight against me like that, and it took forever to get out.
Re: Not An Inxh to Spare
It looked as if it were a random choice of parking spaces, but I have a feeling it was measured beforehand. He couldn't have had more than 6" to spare. How did he know his car would fit in there? I used to be pretty good at parallel parking living in the crowded city as I did. I doubt I could do it very well these days.
Re: Not An Inxh to Spare
I hear ya Yogi!
When I was driving a local tractor/trailer, as a newbie we got stuck with the city deliveries. Most of them were in tiny alleys to loading docks that were nearly impossible to get to. I really did hate those city runs, but on the bright side, I quickly became a pro at maneuvering a big rig in tight quarters.
After that, all of my driving was open road and no physical loading or unloading. I just dropped the box and grabbed another one to head back with. Well, except the short time I drove sand and gravel which is story in and of itself, hi hi.
I've always been able to parallel park without problems, and could even back a car and trailer up narrow driveways off of one lane streets too. Heck, had to do it here numerous times as I made my move south.
When I was driving a local tractor/trailer, as a newbie we got stuck with the city deliveries. Most of them were in tiny alleys to loading docks that were nearly impossible to get to. I really did hate those city runs, but on the bright side, I quickly became a pro at maneuvering a big rig in tight quarters.
After that, all of my driving was open road and no physical loading or unloading. I just dropped the box and grabbed another one to head back with. Well, except the short time I drove sand and gravel which is story in and of itself, hi hi.
I've always been able to parallel park without problems, and could even back a car and trailer up narrow driveways off of one lane streets too. Heck, had to do it here numerous times as I made my move south.
Re: Not An Inxh to Spare
I tried backing up a U-Haul a time or two in my life. Needless to say I didn't make a career of it. I have to admire truckers who can manipulate their trailers with such precision. Do it often enough and it becomes instinct, I suppose. I also must admire those UPS OTR drivers who have two trailers in tandem. They aren't the 53 footers, but still that's a lot of wheels to keep aligned at 70mph. I would also guess they don't back up with those rigs. If they do, I want to see how it's done. LOL
Re: Not An Inxh to Spare
I was licensed for Triple-Trailers. Which is like a misnomer in a way. A tractor Trailer Cab pulling two-trailers is a triple-trailer due to the converter dolly being classified as a trailer. Too dangerous to pull three with #2 and 3 as tongue mounted trailers.
You do have to back up a triple-trailer every once in a while, and yes it is tricky.
Most places you can pull into the spot, drop the second trailer and converter dolly, then back next to it and drop that trailer. Then go back and hook up to the converter dolly and pull it to another parking spot for them. Then go back and connect to whichever trailer you need to back into the loading dock. Pain in the arse and time consuming.
Since you've backed up a regular trailer, you know the angle of the back of your car is what steers the trailer.
Once you have these movements down pat with a single trailer, you can then learn to back a B-train up.
You basically have to get trailer 1 going in the wrong direction to get trailer 2 going in the right direction, then straighten out before you over steer that last trailer. It is tricky, but can be done, if you have enough space, hi hi.
You do have to back up a triple-trailer every once in a while, and yes it is tricky.
Most places you can pull into the spot, drop the second trailer and converter dolly, then back next to it and drop that trailer. Then go back and hook up to the converter dolly and pull it to another parking spot for them. Then go back and connect to whichever trailer you need to back into the loading dock. Pain in the arse and time consuming.
Since you've backed up a regular trailer, you know the angle of the back of your car is what steers the trailer.
Once you have these movements down pat with a single trailer, you can then learn to back a B-train up.
You basically have to get trailer 1 going in the wrong direction to get trailer 2 going in the right direction, then straighten out before you over steer that last trailer. It is tricky, but can be done, if you have enough space, hi hi.
Re: Not An Inxh to Spare
My best guess, after looking over some specs, is that the cab with two trailers is a wash compared to the standard 53 footer. Each of those two trailers are 28.5 feet long. Double that and it amounts to 57 feet which is only four more than the standard trailer. I don't see what is gained by hauling two short trailers. I have seen, by the way, cabs pulling three trailers on rare occasion. Apparently they are not allowed in all states.
You would have laughed at my efforts to back a U-Haul into my driveway. Fortunately it was 2-1/2 cars wide so that I had lots of room for error. I only had a need to do it a couple times in my life, and I think it's not that difficult. One would just need a little practice to make the proper mental adjustments.
You would have laughed at my efforts to back a U-Haul into my driveway. Fortunately it was 2-1/2 cars wide so that I had lots of room for error. I only had a need to do it a couple times in my life, and I think it's not that difficult. One would just need a little practice to make the proper mental adjustments.
Re: Not An Inxh to Spare
The laws are very strict about semi length. Most places it is 70 feet maximum front to rear.
However, on Interstate Highways you can pull longer trailers, but only on the highway, you have to have a location close to the exit where you can pull in and drop a trailer, since you can't pull doubles on most of the smaller roadways.
If you see a B-train pull off at an exit, if you look you will see a Hub or Terminal very near the exit.
It is rare for a terminal to be more than 1/2 to 3/4 mile from the top of the exit ramp.
However, on Interstate Highways you can pull longer trailers, but only on the highway, you have to have a location close to the exit where you can pull in and drop a trailer, since you can't pull doubles on most of the smaller roadways.
If you see a B-train pull off at an exit, if you look you will see a Hub or Terminal very near the exit.
It is rare for a terminal to be more than 1/2 to 3/4 mile from the top of the exit ramp.
Re: Not An Inch to Spare
It's hard enough negotiating driving space with a normal semi. I am glad there are laws prohibiting two and three trailers going down Main Street O'Fallon. The only place I've seen those double trailers are on I-70 and I-55 when I head north to Chicago. I don't think I've ever seen one get off or on the highways, but I'm sure you are right about terminals being very close by.
Re: Not An Inch to Spare
I only drove a B-Train a couple of times, and that was mainly because I didn't want to bobtail it home from Denver with nothing, and all the singles heading back in were taken.
Normally I would pick up a load of meat scraps from the Denver stockyard heading to Bow Wow Dog Food company in Rolla MO, but still had to bobtail it from their back to Fenton to drop of the rig and get my car.
Other than the extra drag, and a little harder on the hills, you really almost forget you have two boxes behind you.
Setting the brake drag is about the only thing that can be tricky. You don't want that back trailer to lock up, but you do want the drag set tighter than the trailer in front of it.
If that back trailers brakes do lock up, you'll see that trailer come around and start passing you, hi hi.
Normally I would pick up a load of meat scraps from the Denver stockyard heading to Bow Wow Dog Food company in Rolla MO, but still had to bobtail it from their back to Fenton to drop of the rig and get my car.
Other than the extra drag, and a little harder on the hills, you really almost forget you have two boxes behind you.
Setting the brake drag is about the only thing that can be tricky. You don't want that back trailer to lock up, but you do want the drag set tighter than the trailer in front of it.
If that back trailers brakes do lock up, you'll see that trailer come around and start passing you, hi hi.
Re: Not An Inch to Spare
"brake drag?" Now you are talking like a flight engineer. LOL Apparently piloting a semi isn't just a matter of applying pressure to the gas peddle and figuring out how to shift through 24 gears. I assumed all the axles were free wheeling, but maybe not. Elon Musk figured out how to make self-driving semis. I'm guessing half the trailer is a computer navigation system. LOL
Re: Not An Inch to Spare
Well, every axle has two brakes, normally. There are a few trailers out there with two axles and only the back axle has a pair of brakes, but this is unusual.
Actually, every trailer has two separate sets of brakes, and/or a single set of self-locking brakes.
They are much more complicated now than back when I was driving. I think they have ABS systems now?
When I was driving, we had a parking brake, besides the self-locking brakes, which usually didn't thus the reason for parking brakes. At that time, self-locking brakes were considered dangerous.
Maybe if I explain it this way. There is a holding brake, aka parking brake, aka emergency brake, on trailers. This brake is actively engaged until air is applied to hold the brake open.
If the air pressure fails, the brakes will engage, but not lock up.
The main brakes are air operated also, only in this case air pressure is what applies the brakes. No air pressure, no brakes. Which is why you don't want to use up all of your air going down long hills, else you won't be able to stop. The emergency brakes are too small to stop a runaway truck on a slope, they are for parking, but can help slow you down on a shallow grade.
Along comes self-locking brakes as part of the main braking system.
On the early systems, it took a certain amount of air pressure to hold the brakes open, the idle position.
They still worked using air pressure to stop like your normal main brake system always has.
But if air pressure is lost completely, the brakes would lock up tighter than a drum.
This is why, although meaning well, they were so dangerous. You lock up those trailer brakes and the next thing you know the back of that trailer is coming around you, hi hi.
An improvement to the self-locking brake system was a bleed tank. If your air brakes failed, the self-locking brakes would not snap to locked, but as the air bled out they worked more like a parking brake, but with more braking power, at least until the air was gone and they did actually lock.
There was a new braking system in use on a few imported trucks about the time I was no longer driving.
These also used air pressure but in reverse. Instead of adding air pressure to the brakes, when you stepped on the brake pedal it lowered the air pressure allowing the brakes to work mechanically, more like the parking brake works, only having the ability to come close to a solid lock up.
These trucks were made almost exclusively for use in mountainous regions of whatever country made them.
After the advent of computers in trucks, long after I was driving, they now have anti-lock brakes. So if you lose your air, instead of skidding, they lock and release, lock and release rapidly to stop the trailer without causing it to skid out.
It's been years since I drove, so I have no idea what other changes may have been made to the brake systems, but I'm sure they are all computer controlled now.
Actually, every trailer has two separate sets of brakes, and/or a single set of self-locking brakes.
They are much more complicated now than back when I was driving. I think they have ABS systems now?
When I was driving, we had a parking brake, besides the self-locking brakes, which usually didn't thus the reason for parking brakes. At that time, self-locking brakes were considered dangerous.
Maybe if I explain it this way. There is a holding brake, aka parking brake, aka emergency brake, on trailers. This brake is actively engaged until air is applied to hold the brake open.
If the air pressure fails, the brakes will engage, but not lock up.
The main brakes are air operated also, only in this case air pressure is what applies the brakes. No air pressure, no brakes. Which is why you don't want to use up all of your air going down long hills, else you won't be able to stop. The emergency brakes are too small to stop a runaway truck on a slope, they are for parking, but can help slow you down on a shallow grade.
Along comes self-locking brakes as part of the main braking system.
On the early systems, it took a certain amount of air pressure to hold the brakes open, the idle position.
They still worked using air pressure to stop like your normal main brake system always has.
But if air pressure is lost completely, the brakes would lock up tighter than a drum.
This is why, although meaning well, they were so dangerous. You lock up those trailer brakes and the next thing you know the back of that trailer is coming around you, hi hi.
An improvement to the self-locking brake system was a bleed tank. If your air brakes failed, the self-locking brakes would not snap to locked, but as the air bled out they worked more like a parking brake, but with more braking power, at least until the air was gone and they did actually lock.
There was a new braking system in use on a few imported trucks about the time I was no longer driving.
These also used air pressure but in reverse. Instead of adding air pressure to the brakes, when you stepped on the brake pedal it lowered the air pressure allowing the brakes to work mechanically, more like the parking brake works, only having the ability to come close to a solid lock up.
These trucks were made almost exclusively for use in mountainous regions of whatever country made them.
After the advent of computers in trucks, long after I was driving, they now have anti-lock brakes. So if you lose your air, instead of skidding, they lock and release, lock and release rapidly to stop the trailer without causing it to skid out.
It's been years since I drove, so I have no idea what other changes may have been made to the brake systems, but I'm sure they are all computer controlled now.
Re: Not An Inch to Spare
That wasn't too difficult to comprehend. LOL When you mentioned drag I imagined brake shoes rubbing against bare metal. That's the formula for smoke and flames if allowed to happen for too long of a time. I never thought about the dynamics of trailer trucks, but I suppose you want that last set of wheels to stay to the rear at all times. I think it would take a fairly sophisticated computer to figure out how to keep the cab and its trailer in line during an emergency stop. Also, I'm guessing the reason compressed air is used on trucks is that it creates a lot higher pressure than could any hydraulic fluid. You can only stomp your foot so hard on the brake pedal.
Re: Not An Inch to Spare
I probably didn't explain it very well. I should have just said, you want the brakes to apply in sequence from back to front of the rig, in progression without locking up the back ones at all.
Like a car, the front tires on the semi rig is what actually does the stopping, but all 18 wheels must be working efficiently so they don't cause other problems like lock-up for a normal stop.
Meaningless numbers here, but it will get the point across better.
When the brake is applied, the farthest back brakes will get 10 psi, the set of brakes in front of those 9 psi, the next trailers back brakes 7 psi, the brakes in front of those 6 psi, and truck back brakes 4 psi, the wheels in front of those 3 psi, and the front brakes 2 psi. Those number multiplied by how far down you press the brake pedal, but equally.
But none of the trailer brakes would actually lock-up, even if you locked up your front wheel brakes.
If all the brakes are properly adjusted, you can make a fast stop without the trailers trying to pass you up, hi hi.
Like a car, the front tires on the semi rig is what actually does the stopping, but all 18 wheels must be working efficiently so they don't cause other problems like lock-up for a normal stop.
Meaningless numbers here, but it will get the point across better.
When the brake is applied, the farthest back brakes will get 10 psi, the set of brakes in front of those 9 psi, the next trailers back brakes 7 psi, the brakes in front of those 6 psi, and truck back brakes 4 psi, the wheels in front of those 3 psi, and the front brakes 2 psi. Those number multiplied by how far down you press the brake pedal, but equally.
But none of the trailer brakes would actually lock-up, even if you locked up your front wheel brakes.
If all the brakes are properly adjusted, you can make a fast stop without the trailers trying to pass you up, hi hi.
Re: Not An Inch to Spare
That last explanation was even easier to understand. You are getting good at this kind of thing. LOL
The physics of it all can't be that complicated, but I'm no engineer. Trucks have been driving the highways safely since forever and they all stop on a dime when necessary. I do wonder when I see pieces of truck tire scattered along the highways. I guess an 18-wheeler can sustain the loss of one tire if it should blow out, but I don't see how they allow tires ready to blow on a truck at all. There are inspections for that kind of thing, no? No doubt it has something to do with costs to replace a tire as opposed to a faulty brake system. In any case, I think I get the idea now. Thanks for the information.
The physics of it all can't be that complicated, but I'm no engineer. Trucks have been driving the highways safely since forever and they all stop on a dime when necessary. I do wonder when I see pieces of truck tire scattered along the highways. I guess an 18-wheeler can sustain the loss of one tire if it should blow out, but I don't see how they allow tires ready to blow on a truck at all. There are inspections for that kind of thing, no? No doubt it has something to do with costs to replace a tire as opposed to a faulty brake system. In any case, I think I get the idea now. Thanks for the information.
Re: Not An Inch to Spare
FWIW: The TREAD on semi truck tires is independent of the Tire itself.
Sorta like the old RECAPPED Tires of years ago.
Those Alligators you see on the road are only the Tread breaking and/or sliding off.
You cannot drive a semi with a flat tire, the tire will heat up and catch fire.
But you can drive on one that lost a tread, at least as far as the next service area that can replace a Tread.
Hopefully you won't damage the grooves the new tread has to slip into.
A new truck tire is really expensive, which is why most of the semi's have independent tread tires.
The tire itself does have a fixed lifespan, and when a certain age is reached, it must be replaced.
Actually it is illegal to put a new tread on a tire that passed its expiration date, for safety reasons.
Sorta like the old RECAPPED Tires of years ago.
Those Alligators you see on the road are only the Tread breaking and/or sliding off.
You cannot drive a semi with a flat tire, the tire will heat up and catch fire.
But you can drive on one that lost a tread, at least as far as the next service area that can replace a Tread.
Hopefully you won't damage the grooves the new tread has to slip into.
A new truck tire is really expensive, which is why most of the semi's have independent tread tires.
The tire itself does have a fixed lifespan, and when a certain age is reached, it must be replaced.
Actually it is illegal to put a new tread on a tire that passed its expiration date, for safety reasons.
Re: Not An Inch to Spare
I learned something new here. i didn't realize truck tires were more than one molded piece. The tires on my Saturn are well over $100 each and I can just imagine what the cost of a truck tire might be. Multiply that times 18 and we are talking major sums of money. So, it makes sense to have removable threads. It's just one of those ideas that doesn't seem likely to work very well. LOL
Re: Not An Inch to Spare
Technically, only the retreaded tires are more than one molded piece.
However, that being said, brand new tires are made in much the same way as retread tires, especially those termed Belted Tires, whether the Belts are Nylon or Steel.
Here is an 8 minute video of the retread operation. It is quite extensive on the operations involved, but also has some wasted time showing other things. Might be worth watching?
https://www.youtube.com/watch?v=PdEWiFuK7X0
By the way, retreaded tires CANNOT be used on your front or steering tires due to the side pressures exerted on them.
A new tire for a semi can cost anywhere from 350 to over 500 dollars each.
The annual maintenance cost on a tractor/trailer is higher than the cost of the truck and trailer.
If you bought a rig for around 150k, it will cost around 180k per year to maintain.
This is one reason why you see so many new trucks on the road and not as many older trucks.
The cost to maintain goes up about 5 to 10% per year.
Recap tires are usually guaranteed for 5 years, however that is not the whole story.
You buy a new truck, it has new tires, these tires only last about 3 to 5 years and have no real guarantee with them.
At about the 3 year mark you replace all the tires for around 8 to 10 grand for new, or 5 to 7 grand for 2 new and the rest recaps. Then after another 3 to 4 years, it is usually cheaper to sell the truck and buy a new one.
Used trucks are usually purchased by local delivery companies and they may run them for another 10 years.
Maintenance costs for local delivery trucks is a whole lot cheaper than OTR trucks. They put on a lot less miles for one, and not much of it is highway driving either.
Ironically, as big as those semi trucks are, there is often less metal in them than is in a full-sized car.
The frame is where all the metal is. The engine is about the same size as a car engine. Most are only 350 Cummins engines as an example.
However, that being said, brand new tires are made in much the same way as retread tires, especially those termed Belted Tires, whether the Belts are Nylon or Steel.
Here is an 8 minute video of the retread operation. It is quite extensive on the operations involved, but also has some wasted time showing other things. Might be worth watching?
https://www.youtube.com/watch?v=PdEWiFuK7X0
By the way, retreaded tires CANNOT be used on your front or steering tires due to the side pressures exerted on them.
A new tire for a semi can cost anywhere from 350 to over 500 dollars each.
The annual maintenance cost on a tractor/trailer is higher than the cost of the truck and trailer.
If you bought a rig for around 150k, it will cost around 180k per year to maintain.
This is one reason why you see so many new trucks on the road and not as many older trucks.
The cost to maintain goes up about 5 to 10% per year.
Recap tires are usually guaranteed for 5 years, however that is not the whole story.
You buy a new truck, it has new tires, these tires only last about 3 to 5 years and have no real guarantee with them.
At about the 3 year mark you replace all the tires for around 8 to 10 grand for new, or 5 to 7 grand for 2 new and the rest recaps. Then after another 3 to 4 years, it is usually cheaper to sell the truck and buy a new one.
Used trucks are usually purchased by local delivery companies and they may run them for another 10 years.
Maintenance costs for local delivery trucks is a whole lot cheaper than OTR trucks. They put on a lot less miles for one, and not much of it is highway driving either.
Ironically, as big as those semi trucks are, there is often less metal in them than is in a full-sized car.
The frame is where all the metal is. The engine is about the same size as a car engine. Most are only 350 Cummins engines as an example.
Re: Not An Inch to Spare
Thanks for the link. The video was pretty interesting and informative. I didn't know, for example, that there was a hot method and a cold method of rethreading. If they gave a reason why one method is preferred over the other, I missed it. The video also says their tyres are guaranteed for 5 years. Why would I ever want to buy a new tire if that's the case?
It's shocking to think that maintenance of OTR vehicles would be $180K per year. As you say, that's more than the cost of the truck. What do they do for that price? I'd expect a 747 jet to cost a lot to maintain, but a truck?
It's shocking to think that maintenance of OTR vehicles would be $180K per year. As you say, that's more than the cost of the truck. What do they do for that price? I'd expect a 747 jet to cost a lot to maintain, but a truck?
Re: Not An Inch to Spare
Well, the trucks I drove often had to have the spline replaced about once a year, more often if they pulled heavy loads through the mountains, or if they pulled two trailers.
There are many more serviceable parts on a semi one doesn't off think of since they are not on cars or small trucks.
I thought that price was high also, but then I thought about each time I was back home from a run and the truck had to go in for service on something. A lot of times it was something minor, but even so, the parts and labor are still expensive, so it adds up pretty quick I suppose.
The rear end in a car normally lasts longer than the car, if it was miked out right at the factory. They usually are.
But semi's have split rear ends, usually triple, some are double. Sometimes the splitting is done inside the transmission, but not usually. A single drive semi has only 5 gears, a split drive has 10 gears, but the most common split drive is 15 gears.
One split is in the transmission, the other two are in the differential. All these extra moving parts, and gears that may not mesh up properly each time can wear out a rear end also fairly fast.
When you drive a car with a stick, you just run through the gears and are in the high gear most of the time.
In trucks, you are constantly shifting up and down in order to maintain speed on even the slightest of hills.
A car with a gasoline engine has an rpm range of about 4 grand, but normally driven within only a 3 grand range.
So they take less gears than a diesel which only has about a 1 grand rpm range.
In a car, when you take off from a stop sign, once rolling you usually shift to second gear, then run the engine up to 3 grand before dropping it into high gear.
In a semi, you are changing gears for about every 500 rpm change in engine speed. We may go through 5 gears before you would be moving into second gear, and another 9 gears before you move into third gear.
That's a lot of wear on the moving parts, and on the clutch, and especially on that spline.
It's not cheap to pull a transmission to replace that spline shaft.
There are many more serviceable parts on a semi one doesn't off think of since they are not on cars or small trucks.
I thought that price was high also, but then I thought about each time I was back home from a run and the truck had to go in for service on something. A lot of times it was something minor, but even so, the parts and labor are still expensive, so it adds up pretty quick I suppose.
The rear end in a car normally lasts longer than the car, if it was miked out right at the factory. They usually are.
But semi's have split rear ends, usually triple, some are double. Sometimes the splitting is done inside the transmission, but not usually. A single drive semi has only 5 gears, a split drive has 10 gears, but the most common split drive is 15 gears.
One split is in the transmission, the other two are in the differential. All these extra moving parts, and gears that may not mesh up properly each time can wear out a rear end also fairly fast.
When you drive a car with a stick, you just run through the gears and are in the high gear most of the time.
In trucks, you are constantly shifting up and down in order to maintain speed on even the slightest of hills.
A car with a gasoline engine has an rpm range of about 4 grand, but normally driven within only a 3 grand range.
So they take less gears than a diesel which only has about a 1 grand rpm range.
In a car, when you take off from a stop sign, once rolling you usually shift to second gear, then run the engine up to 3 grand before dropping it into high gear.
In a semi, you are changing gears for about every 500 rpm change in engine speed. We may go through 5 gears before you would be moving into second gear, and another 9 gears before you move into third gear.
That's a lot of wear on the moving parts, and on the clutch, and especially on that spline.
It's not cheap to pull a transmission to replace that spline shaft.