Battle tank application surfaces for CGI

For the first time, a diesel engine in a main battle tank (MBT) is using a compacted graphite iron (CGI) vee cylinder block.

The South Korean K2 Black Panther MBT is powered by a new engine, the Doosan DST DV27K, which is a 27-litre V12 twin-turbocharged and intercooled diesel with a CGI cylinder block.

The engine can develop nearly 1,500bhp and offer the battle tank a range of 450km. Top speed of the vehicle is 70km/h, although all-terrain speed of 50km/h.

Doosan says the DV27K, with its fully electronically-controlled common rail fuelling system, has a "high-strength cylinder block and a twin-deck cylinder head for efficient cooling. There are separate cooling circuits in order to permit high temperature operation. The engine also has dry-sump oil supply and two-stage air filtration, the former assisting all-terrain operation”.

The DV27K engine brings to three the number of industrial engines with SinterCast process-controlled CGI cylinder blocks – the others being the General Electric locomotive engine and the latest Cummins power unit, the QSK95.

In the first nine months of its current financial year, SinterCast has reported that 60 per cent of its CGI castings’ business is accounted for by the automotive sector, with a further 30 per cent derived from the commercial vehicle sector. This leaves 10 per cent, half of which is automotive-related – bedplates, exhaust manifolds and so on – and the balance is industrial units.

The DV27K is an important addition to SinterCast’s array of engines using CGI, as it demonstrates the high-performance capability of the material in a military environment.

Doosan DST, part of Doosan Corporation, of Seoul, South Korea, describes itself as a specialist manufacturer of fighting vehicles.

In its second quarter 2015 report, SinterCast announced that Doosan Infracore had commissioned its second Mini-System 3000 and begun production of a new 27 litre V12 industrial power engine with a SinterCast-CGI cylinder block, designed for severe duty applications.

SinterCast said then the DV27K engine provides 1,100 kW (1,475 bhp) and was selected by Doosan for its high power, high torque and low noise – all hallmarks of CGI engines. Although the volume is niche, the engine provides another high-performance reference for SinterCast and marks the first CGI production commitment at Doosan Infracore.

Many years ago, Rolls-Royce in the UK developed a V12 turbocharged diesel engine for Britain’s Challenger main battle tank (MBT). Developed at Shrewsbury by engineers at the Rolls-Royce Diesel Engine Division, the engine has been steadily uprated over the years.

The Shrewsbury-based business too has seen changes. It was acquired by Perkins Engines of Peterborough which itself became part of Caterpillar Inc.

The Perkins V12 26-litre Condor engine can develop 1,200bhp (895kW), but has been evaluated by the US Army at a power rating of 1,500bhp (1,120kW).

At this rating, the Condor thus has a specific capacity of 57.7bhp/litre, compared with the South Korean engine of 55.55bhp/litre.

                                       What next for Challenger?

Quite what is going to happen to the British Army’s Challenge 2 MBT remains an open question. Its future could be decided next year. Will it have an uprated engine?

Challenger 2 (CR2) is an advanced main battle tank built by BAE Systems Land Systems (formerly Vickers Defence Systems, then Alvis Vickers Ltd). CR2 is based on the Challenger 1 tank which served on operations in the Gulf War and the Balkans.

Interestingly, only five percent of Challenger 2 components are interchangeable with its predecessor, Challenger 1, which has had no less than over 150 major modifications, including a completely new turret, L30 CHARM 120mm gun and second generation Chobham armour.

Challenger 2's thermal observation and gunnery displays a magnified image for the commander and gunner. The commander has a gyro-stabilised fully panoramic sight with laser range finder and thermal imager.

Challenger 2 entered service with the British Army in June 1998 and the last of the 386 tanks was delivered in April 2002. Deliveries for Oman were completed in 2001. Challenger 2 has seen operational service in Bosnia and Kosovo. British Army Challenger 2 tanks were deployed on active service in Operation Iraqi Freedom. It is said to have a top speed of 59 km/h.

In July 2004, the UK Ministry of Defence announced plans for a reduction of seven Challenger 2 armoured squadrons (about 100 tanks) by March 2007 and the change of role of one Challenger 2 regiment to an armoured reconnaissance regiment.

The UK Ministry of Defence says Challenger 2E, the latest development model, has been designed for the export market and is suitable for harsh environmental and climactic conditions. It claims 2E has been extensively trialled in Greece, Qatar and Saudi Arabia.

Defense News reported recently: ‘Deciding that purchasing a new main battle tank would be too expensive, the British Army will likely stick with what has long been its plan A and proceed with a Challenger 2 life extension project (LEP) starting early next year.’

‘“During the concept phase of CR2 Life Extension Project (LEP) all options, from do nothing to buying a new tank, have been considered. As it stands, the manufacture and costs of a new main battle tank make it unlikely that the Army would seek this option. CR2 will be taken forward and the LEP is scheduled to enter the assessment phase in early 2016,” according to an MoD spokesman. Deciding that purchasing a new main battle tank would be too expensive, the British Army will likely stick with what has long been its plan A and proceed with a Challenger 2 life extension project (LEP) starting early next year, the Ministry of Defence said.’

‘“During the concept phase of CR2 Life Extension Project (LEP) all options, from do nothing to buying a new tank, have been considered. As it stands, the manufacture and costs of a new main battle tank make it unlikely that the Army would seek this option. CR2 will be taken forward and the LEP is scheduled to enter the assessment phase in early 2016,” an MoD spokesman said.’

‘Challenger 2 was essentially sidelined in the 2010 strategic defense and security review (SDSR), with the number of operational tanks slashed and capabilities allowed to atrophy. The question of how to keep Challenger 2 viable was given new impetus by the re-emergence of Russia as a strategic threat and the appearance of the new T-14 Armata main battle tank at a Moscow military parade in April,’ according to Defense News.