In a previous thread about semi trailers it was mentioned that trailers are mostly loaded onto flat cars and spine cars with lift trucks. That brings up the question of how are trailers with side skirts lifted without damaging the skirts? Thanks and Happy New Year to all.
Those skirts are inboard of the lower rail where the lift points are. We have shipped several of our trailers that in order to comply with CARB regulations must be equipped with both Side skirts and trailer tails. They are the only state in the USA that has Mandated these add-ons to all trailers in an effort to lower Emissions. Hello adding more than 700 lbs to my tare weight help how to reduce emissions. I have more weight I drag around all the time now. Our lightest tractor now for the 2017 Model Year with a newest trailer can only carry 45K lbs of freight. 10 years ago our trucks carried 3K lbs more than that. We have lost 1.5 tons of carrying capacity due to EPA mandates. All the emission and other stuff that have been Mandated upon us added weight to the trucks. We are limited in how much we can weigh yet we have to carry an extra 3K lbs in emission and other equipment and the Regualtors want to slap more on us.
Shadow the Cats ownerThose skirts are inboard of the lower rail where the lift points are.
That would only apply to straddle lifting or jacking, where there is no need to reach under the van with forks. I was hoping to hear definitively about how the side skirts were designed to allow forking on trailers that were designed, stressed, and loaded to be handled that way.
When I was tinkering with skirts many years ago, the idea was to put them on sprung posts that could be locked and slid up and down to make room between the top of the skirt and the trailer sill. In some cases this would require compression of the elastomer or fiber 'lower skirt'. Theoretically at least some of the makers (like Strehl) could accommodate this without physically removing or having to unbolt part of the blade cladding.
Another approach was to hinge the cladding (lower down, around the aerodynamic center of imposed loads fore and aft) and align any undertrailer equipment so that the skirts could fold far enough inboard to clear 'fork room' at the sill hardpoints.
We can forestall a Bucyrus-style approach (little 'fork doors' in the cladding) for a variety of reasons, one being that the trailer load can't practically be arranged over just one set of hardpoints, another being that loads can and do shift in transit. The same consideration applied to the idea of jacking trailers by hardpoints in the slider rails and at the kingpin; you have to accommodate to the actual trailer weight at the time of handling automatically, or you're just waiting for the accident to happen to you.
Hello adding more than 700 lbs to my tare weight help how to reduce emissions.
By reducing drag over 7%, and by extension giving lower sfc. If the amount of drag reduction is lower than the resistance due to 700-odd additional lb of mass, you likely either have the wrong blades or you had them installed by morons.
On the other hand, the immediately following point is more relevant:
Our lightest tractor now for the 2017 Model Year with a newest trailer can only carry 45K lbs of freight. 10 years ago our trucks carried 3K lbs more than that. We have lost 1.5 tons of carrying capacity due to EPA mandates.[/quote]
The Feds (and I) are used to saying "the operating cost with aero improvements goes way down because you use less fuel" - which ought to be true. But what comes into discussion here is 'does the saving from the lower fuel burn outweigh the net revenue loss per trip due to the lower lading permitted for a given truck' - I hadn't thought to analyze this across different lanes and load types, and I'd like to see some practical examples.
We are limited in how much we can weigh yet we have to carry an extra 3K lbs in emission and other equipment and the Regulators want to slap more on us.
And I think, quite frankly, that this purely regulatory issue should be addressed by an equally regulatory solution: the effect on loading of these devices, when they are present, should be adjusted out by applying a fixed deduction to scale weight. (I would set this up so that more efficient aero that weighs more gets a higher allowance when the Government tests to verify the efficiency). In fact, I would apply this to items like Airtabs that add only a few lb. of mass to a trailer for their effect, but that show 'good faith' on the part of truckers to reduce drag and hence fuel consumption (or, although this is not directly important, cut down on some of the turbulence and water-throwing experienced by adjacent drivers)
A case could, and probably should, be made for the additional weight of at least some of the mandated pollution equipment, and for any 'anti-idling' APUs.
Cynical domestic-policy observation: adding these allowances to make trucks technically 'overweight' for the few miles beyond a scale or service point it takes to burn off the equivalent in fuel is going to increase "road wear" somewhat. If a national policy attributing the increased damage from trucks on Interstates and other roads to its sources, and insisting the sources provide their appropriate share of the compensation, is then adopted, the higher overall 'road use taxes' or whatever will amount to redistribution of revenue from those truckers with lower aero to higher, which I think is here an appropriate use of public policy tools (and the naive public understanding of "fairness" in how truck regulation is done).
They are fixed in place there is a different model that is just in front of the tandems that would allow it to be picked up via a fork lift style loader. However the added 2 tenth og a MPG with side skirt and .1 MPG with the tail is not worth the extra weight or maintance costs they require. What are the extra costs well spotter truck drivers in some places do not look to see if the tail is deployed and will back right into them crushing them and out goes 2K dollars to replace it. The skirts are about 400 bucks a side to replace our cost at our shop. We ran the numbers and since we rarely run CA we are no longer getting trailers with them on them. Our customer in CA was informed that the costs we incurred will require us to broker aka have another CA complaint carrier haul their loads to them. They understood and agreed to our needs. So we are getting rid of all the skirting and tails in our fleet. We where losing money on the repairs and maintance of the devices so why have them on a trailer.
We run skirts on flatbeds, in part to allow us to be in compliance with CARB. Some of the added weight can be defrayed through specing aluminum trailers and wide base tires. Although it is only California for now, I expect similar regulations will be in place nation and continent wide within the decade. Some of our own customers are already requiring full compliance with Smartway, regardless of the law. They won't load a truck that isn't compliant unless they're really strapped for trucks. I guess platooning is the next frontier..coming to a trucking co. near you over the next couple of years... whatever it takes to drive cost down.
UlrichI guess platooning is the next frontier..coming to a trucking co. near you over the next couple of years... whatever it takes to drive cost down.
What is "Platooning"?
That is the proposed 1 driver in command of up to 4 trucks going down the road. The other 3 are riding in the leaders slipstream. All of the trucks are manned in case the Automatic pilot in the 3 rear trucks fails however the drivers in them are just sitting there doing whatever. The FMCSA is not allowing it past the test track phase at this time. Yet we have CARB and their bunch of idiots that is allowing self Driving 80K lb trucks with that stunt last year.
Yes, "platooning" is the new idea of making self-driving vehicles more fuel efficient by running in highly coordinated groups, with each individual vehicle accelerating and braking at the same time. This will amount to multiple vehicles practicing the so-called "eco-driving" by running at optimum fuel efficient speed, with windows up, and avoiding jackrabbit starts.
It will also have the platooning vehicles "tailgating" in order to cut down on air resistance. That part is the key to fuel efficiency. It is based on self-driving technology being able to coordinate multiple vehciles as though they are one vehicle. This will allow multiple vehicles to run at full speed and be nearly touching each other front-to-back.
This is proposed not only for trucks, but for all self-driving passenger vehicles as well. Highway traffic will be automatically organized according to destination for the purpose of platooning.
Euclid Yes, "platooning" is the new idea of making self-driving vehicles more fuel efficient by running in highly coordinated groups, with each individual vehicle accelerating and braking at the same time. This will amount to multiple vehicles practicing the so-called "eco-driving" by running at optimum fuel efficient speed, with windows up, and avoiding jackrabbit starts. It will also have the platooning vehicles "tailgating" in order to cut down on air resistance. That part is the key to fuel efficiency. It is based on self-driving technology being able to coordinate multiple vehciles as though they are one vehicle. This will allow multiple vehicles to run at full speed and be nearly touching each other front-to-back. This is proposed not only for trucks, but for all self-driving passenger vehicles as well. Highway traffic will be automatically organized according to destination for the purpose of platooning.
First of all, I am not attacking the 'idea' ' platooning' of vehicles; it is certainly, a valid approach to solving the problem.
Secondly, computers can do a lot to assist with that solution. My chief concern, is at the point that 'human nature' comes into the equation. Human foibles being what they are, and the differences in judgement and behavior, as well, are problematic functions of the human psyche. Computers by themselves are pretty predictable, but introducing human behavior into the scenario, exponentially increases the "X" factor into the outcome.
I would suspect that you could have a fairly functional system with one (computer control). With humans involved, daily,we already can experience the potential outcomes- from expected to catastrophic(?).
I am not a fan of the mixing of autonomic vehicles and human operators. Having spent a large amount of days and hours, and years, driving around the country, and Canada. My faith in humanity and its ability to react, in traffic, and weather conditions, leaves me much room for doubt. A statement by an old traffic engineer whom, I worked with and for, is as valid today as it was when he made it. "...Plans for traffic, and its management, work well, as long as you do not count on humans to 'react as predicted' ..."
At risk of going too far off topic, what advantage does platooning offer over the current doubles and triples? And other than extreme length why aren't 53' vans used in doubles and triples?
It just seems to me that the current arrangements of one tractor and driver pulling the equivalent of two 53' gets us 90%already without extra engines or expensive electronic devices.
Modeling the Cleveland and Pittsburgh during the PennCentral era starting on the Cleveland lakefront and ending in Mingo junction
ruderunner has a vaild point.
The Aussies haul multiple trailers with one tractor. Where's the economy of having a tractor for each trailer?
Norm
Certain places in Pennsylvania (I-80 going down the Allegheny front, the middle of PA 33) and in Arizona (I-17 between Phoenix and Flagstaff) - among many others in other states - are simply too steep and dangerous to have anything longer than twin 28's (and sometimes not even those, IMHO).
Otherwise, sounds good on a sunny dry day - but wait until a rainy day, or any snow/ ice conditions. How often do you see a truck pulled over to wait until those conditions improve, unless the road is impassable ? Over here, almost every day with heavy rain has a tail-gating or jack-knifing accident on I-78 between Allentown (PA 100) and Hamburg (US 61). Just another reason I think most trucks belong on the parallel NS Allentown - Reading - Harrisburg line.
- Paul North.
Pulling multiple trailers with one tractor is fine if all trailers are going to the same place. If one trailer is going to receiver X and the other is going to receiver Y which is 50 miles further out, well, then you've got a problem. Also, Australia is relatively flat (compared to North America).. running two or three trailers here poses operational problems involving steep grades and winter weather. One tractor per trailer requires minimal coordination.. i.e. truck is loaded.. driver takes it to the highway where it electronically couples to another unit going in the same direction. At destination they uncouple to go their separate ways. In theory coordination is easy... in practice it is the bane of any business that employs more than two people. This is why large companies have clear step by boring step procedures for getting anything done. I can just imagine how complicated getting one driver to pull three trailers would be.. and that's assuming that such a skilled driver would be readily available on short notice at all times.
Multiple trailers pulled by one tractor is vastly different than platooning multiple rigs. Multiple trailers pulled by one tractor quickly compounds the danger of losing control of the truck as the number of trailers increases.
Platooning maintains the individual trucks, each with the least danger of losing control. Instead of a driver with multiple trailers, platooning is like one driver with multiple trucks. Except the one driver is a computer system.
The biggest difference is that the number of multiple trailers pulled by one tractor is severely limited; while the number of trucks in a platoon is unlimited.
I-81 must be a platoon highway. With platoon A trying to pass platoon B with a speed difference of 0.001 MPH.
Never too old to have a happy childhood!
BaltACD I-81 must be a platoon highway. With platoon A trying to pass platoon B with a speed difference of 0.001 MPH.
Only a matter of time before CSX and NS take a significant number of those off the road.. hard to beat the economics of two people moving a hundred plus loads at a time..
OK, next question:
What if one of the computers in the following rigs decides to punch out for lunch at 60 MPH on a curve in heavy traffic? Yeah, the driver is supposed to take over, right? Chances are he's eating a sandwich. Doesn't that render the point of platooning moot? The dudes in the following trucks are getting paid whether they're driving or not. Savings?
Norm48327 OK, next question: What if one of the computers in the following rigs decides to punch out for lunch at 60 MPH on a curve in heavy traffic? Yeah, the driver is supposed to take over, right? Chances are he's eating a sandwich. Doesn't that render the point of platooning moot? The dudes in the following trucks are getting paid whether they're driving or not. Savings?
Details that remain to be worked out.. which is why platooning isn't happening yet. Drivers in trailing vehicles will be paid a fraction of what a driver who is expected to be in full control of his/her vehicle gets. Likely drivers will take turns being the lead truck. While non leading drivers will be able to get rest or in some cases plan their next loads/get other stuff done. Yes, we trust in the technology to work just as we do now. When you turn the steering wheel in your car you're confident that the car will turn. In the same way people will come to trust the platooning technology..(or maybe not.. who knows).
Yes, I’m afraid the future belongs to platooning. Think of a truck platoon as a freight train with no limit on length. A freight train without flanges on the wheels. A freight train with distributed power on every car. A freight train that can set out and pick up on the fly without stopping.
Some details still need to be worked out. Would a truck pulling a 20K load of TP want another truck with a 48K steel coil hanging 5 feet off his bumper? Hmm.. not this cowboy. I'd rather spend a few cents more on fuel.
I was thinking along the same path. The following drivers are likely to be eating, reading the paper or even taking a nap. But I've come up with a simple solution: replace them with robots.
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"A stranger's just a friend you ain't met yet." --- Dave Gardner
Paul of Covington Norm48327 OK, next question: What if one of the computers in the following rigs decides to punch out for lunch at 60 MPH on a curve in heavy traffic? Yeah, the driver is supposed to take over, right? Chances are he's eating a sandwich. Doesn't that render the point of platooning moot? The dudes in the following trucks are getting paid whether they're driving or not. Savings? I was thinking along the same path. The following drivers are likely to be eating, reading the paper or even taking a nap. But I've come up with a simple solution: replace them with robots.
That's the goal.. platooning is only a stop gap to full automation.
Euclid Yes, I’m afraid the future belongs to platooning. Think of a truck platoon as a freight train with no limit on length. A freight train without flanges on the wheels. A freight train with distributed power on every car. A freight train that can set out and pick up on the fly without stopping.
A freight train that still has 5 to 8 times the rolling resistance of a steel wheel on a steel rail.
All this long distance truck traffic should be "piggyback", to use an outdated term.
Highways would be safer, way less fuel used, fewer stupid people in little cars causing accidents by cutting off trucks that are too big and too heavy.
We could go back to 35' or 40' trailers for local/regional delivery, unclog the Interstates and local roads, save billions in highway maintenence and un-needed upgrades.
They should have deregulated trucking and railroading in 1950, not 1980........this problem might have fixed itself before it even happened.
The world really has lost its mind.......
Sheldon
The rolling resistence argument is overstated. Sure, the flanged wheel is more efficient than the rubber tire, but you're constrained to 3% grades, and the miles add up when you have to go around instead of over the top.
Ulrich The rolling resistence argument is overstated. Sure, the flanged wheel is more efficient than the rubber tire, but you're constrained to 3% grades, and the miles add up when you have to go around instead of over the top.
I'm not in the mood for any more arguments on here, but every set of numbers I have ever seen gives the train 5 times the ton/mile fuel economy of a truck.
Not to mention the safety and other factors sighted above - if any common sense was in play - the train wins this one - but common sense has been outlawed by.......
So I promise, I will shut up now.
And what happens to the drivers of those Smart For 2 cars that decide to exit between trucks? I can hear the "driver/rider/sandwich muncher" saying "Gee, this is a bumpy road". They wont even know they've run over one.
Nothing wrong with a good argument.. I like both modes and earn my living with one.. The sheer number of trucks on the road tells me there must be some kind of advantage to trucking... just sayin..
Norm48327 And what happens to the drivers of those Smart For 2 cars that decide to exit between trucks? I can hear the "driver/rider/sandwich muncher" saying "Gee, this is a bumpy road". They wont even know they've run over one.
A detail that remains to be worked out..
Ulrich Nothing wrong with a good argument.. I like both modes and earn my living with one.. The sheer number of trucks on the road tells me there must be some kind of advantage to trucking... just sayin..
Well, door-to-door delivery is a challenge for the rails.
And the phrase "NOTHNG CAN GO WRONG, GO WRONG, GO WRONG...." comes to mind.
Also the New Yorker cartoon showing a plane crash with the plot parashooting and people rushing toward the crash site, while an engineer walks away with the caption "Well, back to the drawing board"
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