Ripsaw full electric tank

[jackalope]

...Curious to see what the engines are, a 1000hp diesel is not a small lump, especially when coupled with a suitable AC generator, and they also talk about batteries which are also not small items when you consider the power draw of the onboard systems.

Absolutely no idea where they are getting a 1500hp gasoline motor from in 2019...!? The Allison V1710, running jungle juice, doesn't make anywhere near that kind of power for any sustainable length of time, and they have been out of production for quite a while... Military Grade Gasoline is nowhere close to regular Pump petrol, typically 80 vs 87 (for our US viewers, EU RON numbers are calculated slightly differently) so there's no viable route to a modern Turbocharged Direct Injected design that would be practical in service.

This tank uses electric motors much like our R/C tanks do!

The civilian versions that I've seen come with supercharged 7.4 liter Chrvy LS small blocks. All aluminum and 1000hp out of a supercharged 454 is easy to get these days. And yes that 1000hp is on pump gas.

The 6.2 liter supercharged HEMI engines found in the Hellcats are making upwards of 720hp from Dodge. The same 6.2 in the Dodge Demon makes 840hp. Add another 1.2 liters and 1000hp is easy! There are many supercharged and turbocharged 7.4 Chevy (454) and 7.0 (426) liter Dodge HEMI making well in excess of 1000hp and many 1000hp ones are daily driven!

[Von Mooflesaaa]

Got to admit, that it looks awesome.

[Tiger6]

There is a difference between producing an engine that makes 1500hp on a dyno for a few seconds, and producing one that will make that kind of output for many hours.

[jackalope]

There is a difference between producing an engine that makes 1500hp on a dyno for a few seconds, and producing one that will make that kind of output for many hours.

The ones I named will. This tank however has electric motors that make the power, no engine at all.

There's a video of an engine shop who builds jet boat engines that make over 1200hp and they dyno test them by doing 12-15 pulls each lasting 30min at wide open throttle. Numerous engines do so.

And to your point a tank engine doesn't run full tilt the whole time much like any other vehicle..... other then the jet boat engines I mentioned.

[Tiger6]

No, they really don't. Running flat out for a few minutes is not the same as running flat out for a few hundred hours - that is the kind of durability that is required in a military application. There is a really good reason why the current crop of tank engines are 22 litre and upwards V12 diesels.

Actually to add to this - as far as I can recall, a 'typical' standard passenger car engine production sign off test was ~275 hours at constant full load, and then you'd have to pass gross thermal cycle tests for 750 hours or more, and other fun stuff. I've been in the medium duty Diesel engine world for a few years now so I forget the exact test lengths, and likely most of them are customer confidential any way . The engines I am currently working on are expected to achieve 70% of full load, for a B10 life of 8000 hours - i.e. only 10% of components fail after 8000 hours - Now obviously the end user rarely actually does that, but thats the spec he is shopping for. This isn't even Military grade stuff, just general construction equipment. The Military will of course trade more power for less life, but they still expect things to last in the field.

[jackalope]

I didn't notice you posted a link. I don't know why they talk about a diesel engine when they say it's all electric.

[Tiger6]

I suspect that we are looking at 2 different iterations of this concept. The first one the conventionally powered autonomous vehicle in my link, where the engine choices were based on what they had run in the basic Ripsaw vehicle before militarising it - which would explain the bonkers power outputs in such a small vehicle, because it was essencially just a toy that can never use that claimed power for long enough for the lack of durability to be an issue (OEM warrantied water craft engines typically fall into this catagory too, the stated performance usually exceeds the land based version by some margin)

The second version in the youtube link is Textron's marketing folks looking around and seeing what the latest buzz words are, and deciding that they want to showcase an all electric concept. The Ripsaw platform is ideal for this - you are not going to drive a 40 ton Ajax around in spectacular fashion with off the shelf automotive parts, but the Ripsaw is small enough to get away with this.

Just don't ask how far it goes on a single charge...