>> Design trucks and trailers with hydraulic drop-down rail "trucks" (wheel >> sets). Or just the trailers, perhaps. (note, sorry about the long reply, I just was doing the numbers and thought I'd share some) Yep...I think for sure just the trailers.
I am thinking something like a "smart" trailer. Meant to be pulled by a truck on the road with human driver but capable of driving down a train track semi autonomously. Furthermore it wouldbe capable of leaving said track and moving into very very very nearby parking area....again autonomously. The point is to make a sort of battery powered "train" which is probably 6x more efficient (from a energy use standpoint) than a battery powered truck. Obviously the reason is a train of trailers is far more efficient than a single truck and trailer is primarily aerodynamics and and steel wheels are better than rubber wheels (and they don't wear out as fast...truck trailer tires are expensive!). It might look almost exactly like a regular trailer. Most of the magic would be in the undercarriage...with a couple of drop down steel wheels for support and drop down rubber steerable wheels up front for parking and jockeying the trailer First make a trailer capable of doing something like this autonomously..especially with camera's pointing down. https://www.youtube.com/watch?v=TXb32DCeOj0 Then you want another way of jockeying the trailer round to the parking lot. Again I'd think just some drop down steerable rubber wheels that drop down in the front of the trailer and can steer it roundat very low speeds to get to a very very nearby parking lot. Think of it doing something like this...(but with the rubber wheels as I described) built into the trailer. https://www.youtube.com/watch?v=-QGFQ418e2Y Think of how labor intensive it is to separate and move cars in a regular railroad track.....this would be a million times easier. Basically all you need a little land next to the the track...maybe even in the country or something. Let the trailers get on and off the track by themselves and park themselves.....ready to be picked upand towed down a road. I suppose if you could figure out a way to make them charge themselves (imagine at each parking area on the ground there are a couple of charged rails you could access) Make it so a standard regular tractor trailer could just hitch up and go...electric or not electric. Once it's parked and the undercarriage lifted, it's just a standard trailer The worst case requirements are going to be hills so.... So consider a 40,000 lb trailer going up a 3281 feet (1000m) at a 3% grade at 60mph. First the power60mph is 26.8m/s. 40,000lb is 18182 kg So the power requirements are 26.8 m/s * .03 *18182 * 9.8 = 143 kw Then the energymgh = 18182 * 1000 * 9.8 = 178.2 MegaJoules = 49.5 kwh... This is just to put things in perspective. Going down the hill is the same thing, but in reverse...I'm guessing you could recover a bunch of that. Going on the flats is gravy compared to those 2 things. Consider stopping a 40lb trailer going 60mph using 150 kw regen. E=1/2mv2 so 18182/2 * 26.8^2 = 6.5Mj...just in that.So stopping is E = P*T so T = 43.5 sec to stop....I think that's not unreasonable. I don't know about aero...I know it's good. I found something that suggested the coefficient of drag might be 0.12 for a train car because of drafting. ( truck Cd might be 0.7 !) So a regular truck trailer is 13'6 x 102". or 4.1m x 2.6m = 10.66m2 So drag is going to be around D= Cd*p*v*v/2 * Area = 0.12 * 1.2 *26.8 * 26.8 / 2 *10.66 = 551.3 newtons So the power requirements due to drag at 60mph are P = F*V = 14.7 kw ... So on the flats with a 100kwh pack you could go 360 miles or about 6 hours. If you went 30mph you could go 4 times farther or 1440 miles. Anyway, that's just some prelim calc's to get a rough idea. If I made a mistake, I'd appreciate the correction. On Sunday, November 17, 2024 at 12:41:02 PM PST, Peri Hartman via EV <ev@lists.evdl.org> wrote: That's pretty much like what I suggest some time (years ?) ago. Design trucks and trailers with hydraulic drop-down rail "trucks" (wheel sets). Or just the trailers, perhaps. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20241118/8a502dad/attachment.htm> _______________________________________________ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields HELP: http://www.evdl.org/help/
