Diesel engine concept gets go-ahead from UK Ministry of Defence

Diesel engine concept gets go-ahead from UK Ministry of Defence
The Cox Powertrain may find use in Royal Navy vessels such as this one
The Cox Powertrain may find use in Royal Navy vessels such as this one
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CAD model of the Cox Powertrain concept
CAD model of the Cox Powertrain concept
The Cox Powertrain may find use in Royal Navy vessels such as this one
The Cox Powertrain may find use in Royal Navy vessels such as this one

Britain’s Ministry of Defence (MoD) has confirmed that it is continuing funding for a new diesel outboard engine for the Royal Navy’s rigid inflatable craft. Currently under development by Cox Powertrain, the prototype marine engine concept uses opposed pistons. It is part of a policy adopted by NATO countries for converting to heavy oil wherever possible, to simplify logistics and reduce the use of petrol at sea.

Naval forces need a wide variety of fuels to operate. There’s heavy diesel for the ship’s engines, aviation fuels for planes and helicopters, and petrol for small boats. The problem is that these different fuels mean different supply lines and a logistical nightmare during a large deployment, that might see a warship on station without any petrol for the boats.

Worse, petrol is notoriously dangerous to use at sea, with an ever-present hazard of fire or explosion below decks. For this reason, the Royal Navy is joining other NATO countries in converting as much as possible to a single heavy fuel for all vessels.

The Cox Powertrain concept is being developed in collaboration with the engineering R&D firm Ricardo. The project has already attracted £6.7 million (US$10.1 million) in private investment, in addition to previous MoD funding. The concept is based on an invention of Cox Powertain’s founder, former F1 designer David Cox, and is specifically designed for outboard use.

CAD model of the Cox Powertrain concept
CAD model of the Cox Powertrain concept

The concept uses opposed pistons, which means that the super-charged. two-stroke 3.6-liter motor has eight pistons housed in four cylinders. There’s no cylinder head, but rather each cylinder uses a centrally-placed injector, and the piston pair compresses the fuel/air mixture in the middle. Meanwhile, a Scotch Yoke crankshaft converts the reciprocating movement of the pistons into rotary motion.

With this layout, the Cox Powertrain concept achieves 350 bhp (261 kW) per engine module, yet is half the size of an equivalent conventional diesel engine. It can also be configured in multiple modules up to 700 bhp (522 kW).

The Cox Powertrain concept has completed its detailed design phase and the first firing is expected this month at Ricardo. The companies also foresee the development of variations for civilian applications and UAVs.

Source: Ricardo

Denis Klanac
Not a new invention just an adaptation of an old deltic engine used in locomotive in the uk.
Apart from heavy crude oil use and a more compact size, what are the other advantages for this design's use in an aquatic environment?
Why aren't they using porsche or subaru engine which is exactly what we call a flat engine?
Also, they could have put their money inside a better engine like the liquidpiston engine which is suppose to be really smaller...
Michael Mantion
350 bhp impressive.. I love compression ignition and I am really glad they are going forward with this.. I just wish they were pushing to develop some of the more radical layouts.
The engine strikes me as being somewhat overly complicated but sometimes it's worth the effort.
Anthony Collett
Why would you need 350bhp to power such a small boat? If you must chase drug runners surely its cheaper to use the heat seeking weaponry which is already available to them.
Mitch Slagghorn
A multi-fuel Diesel block is certainly the most versatile fuel option and a scotch yoke may also offer a cylinder(s) shut down option as well. As a marine block constructed for maintained high rpm's, I would suspect that this would be a very sturdy casting. If the yoke were made right, it might help in a supercharging config. It would be neat to combine this engine with a pair of Holden Battery packs for a 4WD Hybrid Vehicle application.
You saw it here first.. well actually... no,, this was first:
re; Anthony Collett
In places ruled by Law killing people suspected of committing a crime is murder. Also heat seeking weapons are very expensive.
Fritz Menzel
Ah, if only automakers could be as "motivated" (showered by tax dollars) as defense departments, what a wonderful world this would be.
Geoff Smale
Why would you waste money developing this when the USA navy has already done it? Every level of Government believes their needs are special no wonder taxes are so hi
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