Electric (road) train

[Piwoslaw]

Originally Posted by Ecky

That aside, designing a system from the ground-up to operate on roads, I'd go with a powertrain similar to how diesel trains operate. Which is to say, electric motor at the wheels, with the engine acting as a generator. This gives the option to choose a battery size (or not at all) to have some electric-only range, downsize the engine, and get rid of the transmission.

What about your idea plus a simple 1-speed transmission used at cruising speed, while the electric gen/motor used de-/acceleration?

[Ecky]

Originally Posted by Piwoslaw

What about your idea plus a simple 1-speed transmission used at cruising speed, while the electric gen/motor used de-/acceleration?

It would be ideal, yes.

[Xist]

Originally Posted by redpoint5

Looks fun to back up!

In the Army, we would pull forward until the truck and trailer were perfectly straight, and then insert a backing pin, but here that would result in a 50% longer tractor.

[JSH]

Originally Posted by redpoint5

I wonder if that might be part of the delay of Tesla getting the semi to market? Jason would be better informed.

Biggest issue keeping the Tesla Semi off the road is the lack of a factory to build them. I'd say the second is a lack of a dealer network - fleets expect warranty repairs to be completed within 24 hours. Then there the completely unproven design with several very stupid design decisions.

Originally Posted by redpoint5

As a tangent, AI is saying fuel represents about 25% of trucking operating costs, which is 2nd to driver wages. My guess is electric "fuel" could cut that cost by 2/3rd. Charging would then represent about 10% of the operating cost.

Correct. The largest trucking cost is the driver followed by fuel
2024 ATRI Average cost per mile:

$0.995 - Driver
$0.481 - Fuel
$0.390 - Truck Lease / Purchase Payments
$0.190 - Maintenance
$0.102 - Insurance
$0.047 - Tires
$0.038 - Tolls
$0.009 - Permits / Licenses
$2.260 - Total

That explains the push for autonomous driving in the commercial sector.

[redpoint5]

Originally Posted by JSH

Then there the completely unproven design with several very stupid design decisions.

What are the stupid design decisions?

I was surprised insurance is 10 cents a mile, and tires 5 cents.

If autonomous trucks could just handle the long haul freeway sections, with a human driver taking over as it approaches the city, that alone would save a ton.

[Piotrsko]

Tires are stupid expensive when there's 16-18 on a truck at a three-four hundred a pop mounted but not installed, assuming your company does not run retreads. You aint gonna get 15,000 miles off a set either, and don't forget periodic random roadside inspections.

Insurance.... cant live with it, cant drive without it (easily ) I think Cali still has a bond alternative, but tieing up a couple million in a bond is no longer cost effective

[JSH]

Originally Posted by redpoint5

What are the stupid design decisions?

Big one is the centered driving position - which just gives you two smaller forward blind spots while preventing the driver from being able to roll down the window and physically look at the trailer when backing Plenty of trucks have mirror cams but drivers tend to trust their own eyes more.

That centered seat also means that the passenger seat is staggered behind the driver with a flip down jump seat. It also mean that that the driver can't just hand paperwork out of his window to a dock worker or security person at the gate. Instead he has to put it is park, get out of the seat, walk back to the door that is behind the seat and open it. The staggered seat also makes the cab longer - which is a problem for places with length restrictions. I can pretty much guarantee that none of the large fleets asked for a seat in the center of the cab - if Tesla even bothered to ask for customer feedback.

Originally Posted by redpoint5

If autonomous trucks could just handle the long haul freeway sections, with a human driver taking over as it approaches the city, that alone would save a ton.

That is the plan. Human picks up the load from the dock and takes it to a switching hub right off the highway. The trailer gets switched to an autonomous truck that gets a DOT inspection and sent on its way. It goes 200, 300, 500 miles down the highway to the next hub where it gets refueled and another DOT check. If that is the final destination it gets switched to a human that takes it to the delivery dock. If not it gets sent out on the highway again for another 200, 300, 500 miles to the next hub. An autonomous truck does not need to follow DOT rules on hours per day and can realistically drive 22 hours per day.

It is already happening today with companies operating completely autonomous class 8 trucks with no safety driver in Texas. (Texas was picked for early routes do to regulations and weather)

[redpoint5]

Originally Posted by JSH

Big one is the centered driving position - which just gives you two smaller forward blind spots while preventing the driver from being able to roll down the window and physically look at the trailer when backing Plenty of trucks have mirror cams but drivers tend to trust their own eyes more.

I'd expect that error to get corrected quickly.

I still can't back a trailer up using video, as I learned looking over my shoulder. Not only that, but a screen lacks depth perception. Looking over my shoulder I have peripheral awareness and can see exactly how close to things I am.

Perhaps backup screens need parallax so depth perception can work.

[pete c]

I could see such a device being usefull out west where you have some very long pulls to get over a mountain.

Imagine you have a center of highway parking lot where you can hook up/ drop off.

At the bottom of the mountain, you pull in, drop your trailer. The lot attendant uses a little yard truck to move one of these fully charged units onto your trailer.

You take it up and over. You save fuel and brakes and drop off a charged unit for someone headed the other way.

[Ecky]

Originally Posted by pete c

I could see such a device being usefull out west where you have some very long pulls to get over a mountain.

Imagine you have a center of highway parking lot where you can hook up/ drop off.

At the bottom of the mountain, you pull in, drop your trailer. The lot attendant uses a little yard truck to move one of these fully charged units onto your trailer.

You take it up and over. You save fuel and brakes and drop off a charged unit for someone headed the other way.

While I agree this would be an improvement, if you're disconnecting the trailer, you might as well just pull it over the mountain on a train at that point. Which is how most of this cargo should be moving anyway.