Just a question here. I’m not an engineer of any kind, so I’ll just ask.
For decades, inland temperature controll systems in transport have had small diesel gensets that provide power to electric refrigeration systems on a trailer/container/railcar.
OK, on rail, could you do it with the newer design batteries? Maybe it would save some money and increase the competitiveness of rail vis a vis trucking. Put the batteries on the railcar and hook 'em up. There’s less of a weight probem on rail than on the road. Of course, you’d have to provide power on the truck portion for intermodal. PTO off the highway tractor?
There’s a huge volume of this stuff moving long distances by truck in North America. Could it be to the railroads competitive advantage to use batteries instead of gensets? It’s conceivably possible in my non engineer mind to even recharge the batteries from downgrade braking or solar pannels.
I’d simply note this: for Elon Musk to achieve his class 8 electric truck ‘future’ all the necessary engineering either has or will be done ‘for you’ – as will much of the technology and even the capital buildout. Scaling the number of cells in parallel is the only thing needed for even large insulated cars.
The other ‘half’ of the picture is good aerogel and nanoinsulation, which can probably cut down the actual heat-pumping required by a substantial amount. I understand that less than an inch of good multiple-shield insulation has the same quality as some of the ‘space-grade’ systems used on rockets in the 1960s with much more cost and thickness.
There are a variety of charging options, including the equivalent of wayside storage charging; I suspect that some kind of harness on well cars analogous to HEP is going to be the thing, but the 220V line from ECP braking could be used for trickle-charging and ‘emergency’ support power with a little enhancement. It might even be possible to have a percentage of combustion-engined ‘hybrid’ power distributed in the consist to do any ‘support’ charging for end-to-end QoS that large battery banks alone might not be cost-effective or safe enough to handle.
Thank you Overmod. It’s refreshing to have someone contribute to a concept instead of listing 1,001 reasons why it won’t possibly work.
I did take a look at Tesla’s prototype highway tractor. It seems well suited for intermodal pick up and delivery. The highway range is more than sufficient. Maybe it could also provide the power to a container’s electric refrigeration system while on the road. That would eliminate the need for a diesel engine, fuel, and generator on the container. This would save weight, something that is critical in reefer movements. It would also save investment expense and maintenance.
Tesla claims its tractors can out accelerate and out pull a diesel tractor on the road. If that’s true, the batteries from one of those things should be able (in my non engineer mind) to provide electric power for an six pack of refrigerated containers on an articulated well car for quite a distance.
There is a little more involved here, which you can appreciate a little better by reading up on "Ludicrous-plus’ mode in Tesla cars.
By temporarily replacing ‘best battery management’ with full-tilt managed discharge, Tesla can produce very high effective acceleration for ‘the time needed for the vehicle to come up to speed’. In the bad old days (not too long ago for many cell constructions) frequent use of such a ‘mode’ would produce early battery damage and perhaps progressive weakening of capacity/early aging, as well as some weakening of the motor magnets due to exceeding the Curie point in permag structure.
This is different from sizing the pack for sustained heavy use, for example grade climbing or bucking sustained heavy headwind. Your consideration for containers would be whatever maintenance drain a refrigerator for a well-insulated volume involves – a major consideration of course being ‘prechill’ of the load using fixed power or equipment whenever possible. I’d design shore power, including that used during traction-battery ‘megacharge’, and probably the anti-idling arrangements used for hybrid trucks, to include the necessary current capability.
You would, I think, be correct in thinking that a ‘traction battery’ from a class 8 truck would be capable of supporting several efficient refrigerated containers – perhaps a surprising number, if ‘make-up’ of thermal losses through insulation during on-rail transit is the principal anticipated draw. It would be interesting to consider whether changes to discharge-
Well, I don’t know about the Memphis Grizzlies, but repeating it three times doesn’t change the fact that I understand about 1/3 of what he said. I flat out don’t know what a “Curie point” is. Overmod seems to know his stuff, but he does usually talk well over my head. That’s my problem, not his.
So, putting this all together as best I can…
It looks as if there may be an opportunity to:
Use the lighter weight Tesla tractors (300 mile range) for intermodal dayage. California will be happy and it could make economic sense.
Power refrigerated containers from those tractors when on the highway.
Power refrigerated containers from well car mounted battery packs while on the railroad.
Link a generator to a well car axle to recharge the batteries if necessary.
There is a huge opportunity for the railroads in the normally longer haul movement of fresh vegetables, fruits, meats, poultry, etc. This might help them exploit that opportunity.
No, it’s mine for talking over your head. Remember how on the English-grammar threads the point is made about ‘communication’ being the point of these forum posts? Well, the opposite or contrapositive is true, too: no matter how correct the grammar or ‘fascinating’ the cogitation, if the reader doesn’t get what they need, it’s the explanation that needs the rework, not the reader.
In case anyone has noticed I had this problem in the entropy thread, too.
The ‘Curie point’ is the (usually ‘elevated’) temperature at which a substance that exhibits ‘magnetism’ stops doing so. This is observed to be reversible for temporarily-magnetized materials (e.g. ‘ferromagnetic’ metals and alloys) but in many permanent-magnet materials repeated heat cycling above the Curie point will result in progressive loss of
One thought on the “Spicer drive” idea. Instead of having the generators sized to float charge the batteries as was done on axle driven generator passenger cars, size the generators to be able to act as regenerative brakes to recharge the batteries when braking is needed. Use induction generators to miminize drag when not charging - permanent magnet generators will have some core loss increasing drag above what’s caused by friction and windage.
Virtually all of our passenger cars still have the axle driven generator still in place (it’s heavy, and removing it will require some “rebalancing” of the car/trucks to ensure proper ride). They were driven by a right-angle drive off the center of the axle. The drive shafts, etc, are long gone on our cars. Aside from the FRA frowning on them, I suspect they’d be a maintenance headache of the first degree.
I recall seeing that container ships have a mechanism to plug in the refer units so they would run off the ships power in transit.
Seems like having a power bus on a certain number of well cars with a container filled with batteries that get recharged from the locomotives via regular power or by harvesting regenerated power from dynamic braking would be somewhat feasible.
Maybe not in PSR world as this would be dedicated equipment.
Spicer drives are not highly workable on three-piece trucks for a number of mechanical reasons; Amtrak has recently banned them as if they seize or the shafts lose a universal and drop it can cause spectacular derailment with little warning.
You would not want something under distributed wireless control to make up part of your dynamic braking. Again for a variety of reasons. It’s an appealing idea to use the bazaar software-development model for train handling – but I see too many pitfalls for not enough assured safety.
On the other hand, we could use the distributed battery storage as the source for the functional electromagnetic track emergency brakes we were discussing a few years ago, as I think they have the necessary energy density. On even semi-dedicated consists this might prove of real value.
I’d use switched-reluctance (double-salient) generators since we are assuming full control over the various excitation currents. I’d provide either a small permag-enhanced exciter or some other external ‘voltage source’ for excitation from ‘dead’, as I did with the intelligent-driveshaft ‘fix’ for SPVs lo! these many years ago. I agree that using equipment with as little undesired ‘machine friction’ effect as possible, including effects of continual self-induction via eddy currents from permanent magnets, is probably a good idea.
I still favor the use of Gates belts driven from a
I agree in that a caboose generator belt arrangement would be best. It may also make sense to have at least two generators per car so that a belt failure dows not mean total loss of power.
The intent with using the generators as auxiliary brakes is NOT to be the primary brake mechanism, but as a way of scavenging energy that would otherwise be wasted. OTOH, some sort of higher powered axle generator could be interesting for a commuter coach. In this case, the generator would be in a form of traction motor mounting.
No, just the opposite: on a railroad, checking the fancy technology and fixing it when, not if, it breaks is a very important priority – perhaps the greatest, long-term.
I am presuming that adequate BITE is provided in the control equipment, that the design takes full advantage of modular and FRU construction, that logistics exist to get parts where needed, that there is full support for manuals and support on wireless devices in the field … etc.
And that the design isn’t characteristic of modern “Internet-style” design practice, where the philosophy is not to test the complex rigorously but cleverly troubleshoot ‘around’ complex failures as they emerge. That philosophy is highly useful in building self-healing networks for global thermonuclear war, not so much in building software that has to be maintained by anyone but gamers. It certainly destroyed Yahoo Groups about as effectively as I’ve ever seen an industry-leading organization destroyed; up to that point I thought RIM’s implosion was about the worst thing that could happen.
I learned early about the value (at least in theory) of field-replaceable parts, for example the original idea of the RDC engines which pioneered ‘works-in-a-drawer’ decades before Quasar. Much of the maintenance of an onboard ‘hotel-power’ system (whether to run refrigeration or just trickle-charge it) would be conducted by replacing components wholesale, including both on a PM basis and as monitoring software advises, and servicing them ‘asynchronously’ as time and budget and facilities (and offshore shopping, perhaps) permit. Emergency maintenance ought to be limited, where possible, to what one man ‘on the spot’ could transport there, perhaps by drone, but if not…
Today’s PSR railroads abhor spending money on maintenance - they feel it is money better spent in shareholder value. Anything that will require additional funds to be spent to maintain it is DOA.
They don’t want to ‘touch’ locomotives beyond putting fuel and sand in them while occasionally emptying the toilet between required 92 day inspections (which requirement they are trying to have the period extended). Likewise they don’t want to touch freight cars more frequently than FRA regulations require.
TBH this was often the attitude long before the advent of three-letter things like EHH and PSR. It’s been argued, I think with more than a grain of factual truth, that things like the Power Brake Law and the Boiler Law were driven by railroad obstinacy to act in what was, honestly, their own greater best interest – and yes, there are parallels in the likely course of adopting ECP. The great first-generation dieselization was at its root a desire to make locomotives less complicated to service and to operate … and over the years the innovations that have been adopted on locomotives, as opposed to those that ‘died on the vine’ or were outright disasters like the Republic Starships, have often been those that reduce uncertainty, or predict a ‘maintenance’ schedule without human intervention, or that allow locomotives with some defects to operate until ‘schedulably close’ to their 92-day or whatever.
And truth to tell, if I were running a railroad I’d pay careful attention to all that, and be tempted not to do anything I didn’t actually ‘have’ to do – there are no government guarantee programs or aid for spending money on them if it turns out you need the capital elsewhere, and not just to line stakeholder pockets as an ‘incentive to invest’ or to keep the share price up when you want it high or whatever.
I’d presume that the cost of maintaining and ‘spot-repairing’ any of the electrical equipment on the cars would be handled comparably to how ‘private cars’ are currently maintained: the railroad or a contractor suitable to it would repair