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Pride of the fleet

George Coupe
Controversy has dogged plans for the Royal Navy's new fleet of aircraft carriers. Chief naval architect Simon Knight talks to George Coupe about the negotiations to keep the ship on schedule and to budget.

UK defence contracts have a habit of sailing into troubled waters, and the Royal Navy's new fleet of aircraft carriers is no exception.

Controversy has surrounded the project to build the two 60,000-ton Future Carriers ever since it was announced that the work would be shared between BAE Systems and Thales, the part-French government-owned defence contractor. BAE Systems is to prime the build, and the boats will be constructed to Thales' designs.

BAE Systems is the UK's largest defence contractor and has a difficult relationship with the MoD and has recently made heavy losses on the Nimrod aircraft and Astute submarine programmes.

Last month the company was reported to have warned the government that it would not be able to build the two ships for the original price of £2.8bn. It was said that unless costs were allowed to rise to £4bn the vessels would have to be reduced in size and the number of aircraft they could carry would also be cut from 48 to as few as 20.

This would be a serious blow to plans for the future structure of the UK fleet. The two vessels, which will be the largest warships this country has ever seen, are central to the UK's flexible strike capability. The rest of the fleet has been reduced and reorganised around them and the Navy has eagerly anticipated what the designers described as the Holy Grail of aircraft carriers. Each was to be equipped with technologies such as automated weapons-handling systems and the best in command-and-control capabilities that would allow personnel to direct operations from onboard and integrate with the US battle groups (see sidebar).

The reports of possible cutbacks were played down by the MoD and BAE Systems. A final price for the ships is not actually due to be agreed until April 2004, when the project reaches 'main gate' - the point when the final contract is signed and detailed design work will begin. Such pre-contract negotiations are 'normal' ahead of final signing, said BAE Systems.

This may well be the case, but the Future Carrier project's chief naval architect has revealed that his team is in the process of an intensive cost trade-off process with the customer to reduce the price of the ship.

So far this has involved stripping out some of the more sophisticated systems onboard and reducing levels of automation and will also include a possible reduction in the size of the vessel.

Simon Knight is leading a team of naval architects at BMT Defence Services based in Bath and Bristol. BMT is an independent house of naval architects, contracted to Thales, and has remained out of the media spotlight in the carrier row so far. Knight is responsible for designing the carrier platform itself which includes the structure and layout of the vessel, all the platform systems such as powering, stability, survivability, defence signatures, shock protection and separation.

He also chairs the weekly integral working group of representatives from the other design areas, which include mission systems and engines.

From 1996 to 1998 he was the chief naval architect on the Astute submarine programme, and is a veteran of several other major MoD naval contracts. From his position at the heart of the carrier project he is able to give an insight into the background to the latest negotiations between the MoD and its appointed contractors.

Knight is scathing of current MoD procurement practices and warns that the entire project could be heading for trouble if the cost trade-off process is allowed to go too far. In his version of events the blame for the increase in the price of the two ships cannot be laid at BAE Systems' door. The original brief was for a carrier capable of carrying 48 aircraft.

'Both Thales and BAE came out of the assessment phase with pretty much the same size ship, about 290m in length overall,' he said. 'What was even more surprising was that the price was the same, but for different reasons. Since then what the customer did was to select our ship design and take certain aspects of the BAE solution, principally the mission systems, and put it into the Thales ship. Those systems were the most expensive systems and that meant the price went up.

'What we are trying to do now is to see if we can get the price down and one of the trade-offs is to look at if we can have a smaller size of ship. But principally we are trying to take out some of the excess functionality. What we almost had before was a ship that could be a frigate in terms of its self-defence capabilities, and that could be a command-and-control ship in terms of its communications. It was the Holy Grail in terms of everything, and we are trying now to pare back to just the aircraft carrier role.'

The Royal Navy in particular wanted the carrier to be a fully enabled command-and-control centre from where personnel could direct operations on land and sea and integrate into the US military command infrastructure.

Knight confirmed there would have to be a compromise on this front now. 'Steel is the most expensive component of the ship, but after that it is the mission systems area. But you would expect the carrier never to sail on its own. It would always have a fleet of Type 45s around it. If the 45s have got all the latest communications and sensors onboard why put them on the carrier as well?'

He said he could not name the specific systems that would be removed but described the resultant ship as a 'halfway house' between the most basic floating runway and the original brief. The cost trade-off that has been underway for several months is likely to continue right up to main gate and beyond, said Knight.

He indicated that the construction schedule for the ships is tight: the yards are due to start cutting steel in 2006, and the first vessel is due to be launched in 2009 to begin its sea trials. This means there are only two years to fully finalise the design and three years to build the first carrier.

He warned that the cost trade-off process, combined with the common practice of consulting at length with the MoD's bank of experts or stakeholders over the specifications, could send the project adrift - a problem that he experienced on the Astute programme.

'I was quietly going mad on that [Astute] because I was working in a project environment with people who were very much process oriented and not actually product oriented.'

He is critical of practices that channel efforts into drawing up management plans for addressing issues, for example of stability, rather than getting on with stability calculations themselves. He is also dismissive of the drive to build ever closer relationships with suppliers - a feature of the government's Smart Acquisition philosophy, which was pioneered on the Astute programme.

According to Knight, Smart Acquisition has failed. 'What is supposed to happen is that the MoD gives 10 fundamental requirements and leaves the designers to come up with the best solution and work as an integrated team. That just can't work when you have two competitors because the MoD must be hands-off, so it is not an integrated team. Second, the MoD has got so many stakeholders, especially with the aircraft carrier, that we've had people crawling all over us asking us to justify each decision.

'There are people within the MoD saying why don't you take this system that we have spent thousands of pounds of taxpayers' money developing when you could take an off-the-shelf system that is much cheaper. The MoD needs to fundamentally change how it is set up and how it wants to do its business if it really wants to work in smart procurement.'

Knight said that the change needs to be made soon or the carrier project could suffer the same problems as the Astute contract.

'When the carrier was still a bid it was almost easier. We could speak to the MoD and say we will choose what we feel is best. Now it isn't a bid - the MoD and all its stakeholders are into us much more and demanding that we justify everything fully on paper from engine choice right down to the type of piping material, to all the individual stakeholders, which we just can't do. We are going to spend years and years on this trying to sort it out, which is part of the reason why the submarine programme has gone adrift.'

However, the tight timetable might bring unforeseen benefits, said Knight. He and his team are determined to hang on to the principle that size is all. In an aside he said that should the ship get any smaller it would not be an aircraft carrier at all, and where space onboard is concerned it is vital that there is room enough to cater for the principal payload - which is the pilots. This means devoting valuable space to their accommodation.

'Probably this latest cost trade-off exercise has actually let us be more ruthless and has given us the power to say, 'This is the system that we are going for. If you don't like it then you need to go away and justify why we need to change.''

Meanwhile, Knight hopes that his strategy of 'derisking' the build programme as far as possible before work starts in 2006 will help to keep the project on track. Traditionally the general arrangements of a ship would be handed over to the yard before the detailed design work is fully finalised.

'This has not worked well in the past. Steel has been ordered and because of the payment milestones things have been built that have been wrong.'

'What you typically go to main gate with is a ship that is just past the feasibility level, so for example you have not really sorted out all the structure yet, you certainly have not got any suppliers onboard.'

'With this project we are past the feasibility level now. We are doing a few big trade-offs, but by the time we get to main gate we will be much more mature than we have ever been in any past naval programme. So when we do hand over to the yards it will be much clearer what each yard is actually doing and there will be a frozen product which they can build and start to order.'

Knight's strategy is a sound one. But it seems there are many difficult hurdles yet to be cleared. Knight's comments on the MoD's method of doing business, and the dangers of making a compromise too far on the Future Carrier may make uncomfortable reading for many people involved in the project and the industry at large. But they should be noted, not least because public attention is now focusing ever more keenly on the carrier project.

If the government delivers a ship that is less than the public or the Navy rightly or wrongly expect, they risk a major storm - of the political variety.

SIDEBAR: Innovation helps keep the price down

The Royal Navy's new carriers will include a number of technical innovations that have been employed to make best use of the space available, boost the ships' capabilities and reduce the manpower requirements. As always the size and capability of the vessel must be balanced against cost. One way of improving the trade-off was to make the ship easier to build. 'Derisking' the build process as much as possible also helps to avoid delays and expensive mistakes.

On previous naval contracts work has often started before the design of the ship has been fully finalised. This can lead to problems later on when services come to be routed through the ship and equipment is installed. So almost the first job for the designers was to figure out a network of dedicated passages to take cables, ducts and pipes. It is around these that the other spacial interactions are determined.

For the same reasons of simplicity and cost the designers have also employed a number of conventions that have been tried and tested on commercial shipping.

For example, previous naval hulls have been of a lightweight construction, those that give the 'starved horse' effect. This characteristic is produced when the relatively thin hull plating actually bows around the closely spaced ribs of the ship. While this design of hull is of minimal weight, it also makes for a relatively flexible structure and so is resistant to shock loads. However, it is difficult to build when compared to the conventional system that relies on heavier plating and hull stiffeners which are wider apart. The ship will also have a simple hull form, again taken from the world of commercial shipping. Warship hulls are usually rounded to improve speed, and they include many areas of double curvature. However, the new UK carriers will have a large section of parallel middle body, which again is easier to construct.

'It does have an effect on the speed of the ship,' said Simon Knight of naval architects BMT Defence Services. 'Warships have to go fast but with a carrier it depends on the aircraft. If you are using a catapult (to launch aircraft) there is a trade-off between that and the speed of the ship, although not so much with the short take-off and vertical landing (STOVL) jet. We did careful trade-offs and came to a speed we thought would be appropriate.'

Where the design will deviate significantly from convention is in the use of twin islands, the so-called superstructures that sit on the flight deck. When the competing designs were presented to defence secretary Geoff Hoon last year his only question was why use a twin island configuration.

It is always important to maximise the area of the flight deck. But the island must be large enough to house the bridge, flight-control centre and sensors such as radar. 'We found the best place to put the island was on the forward starboard quarter, similar to the French carrier [Charles de Gaulle],' said Knight. 'So we put the bridge and the flight control there and we found immediately that we did not have enough room for the sensors.'

In any warship design there is a need to separate. It is better not to put all the engines or sensors in one place. It is also better to have the shortest possible length of ducting from the engine rooms up to the islands. Widely spaced engine rooms and only a single island would have necessitated ducting the uptakes along a tortuous route through the ship. The serving carriers have a narrowed hanger where space has been made to accommodate the ducts.

'We were also worried about where the forward starboard catapult would go and the space around that for manoeuvring aircraft preparing for take-off. So then we looked at a second island.'

The second island allowed the ship to have a flight-control centre that principally looks aft, rather than forward, as the most critical 'evolution' is when the aircraft are landing. The two smaller islands also give much more 'parking space' for aircraft on deck. A further innovation will be the use of deck-edge lifts. Most carriers have lifts within the deck itself, sometimes in the runway, which can cause problems if the lifts get stuck.

However, deck-edge lifts can only be fitted on ships that are upwards of a certain size. If the carrier weight falls dramatically during the cost trade-off this might be one of the design features that would have to be reconsidered. In a smaller ship the lifts would have to be heavily engineered to cope with the movements of the vessel in rough waters. At present the lifts would be capable of carrying a 70-ton load, equivalent to two aircraft. The lift itself will weigh about 40 tons.

'To make it sea-kindly for the sea loads that we are looking at we would need a huge increase in the weight of the lift and hence a huge increase in the mechanisms used to control the lift. If you have a big ship its motions are going to be much less.'

SIDEBAR:First major warship to have pod engines

The future carrier will be the first major warship to be fitted with pod engines. Only the Royal Navy's 3,500-ton Echo and Enterprise survey vessels carry two electrically powered pods of 1.5MW each. The new carriers will be powered by four 21.5MW pods.

'The reason we went for those is they save us space within the ships, and for an aircraft carrier you can use them to manoeuvre more easily. Each pod steers in 180 degrees and with the bow thrusters the vessel can self-berth,' said Simon Knight of naval architects BMT Defence Services.

His design team has been in close touch with Alstom's Chantiers de l'Atlantique shipyard in Saint Nazaire, which is building the Queen Mary II, one of the first passenger liners to be powered by pod engines. Pods were specified for the future carrier to further reduce the risk of delays and problems during build. In a 'shafted' solution, the shaft itself, the bearings, thrust blocks and other components have to be put into the ship early on. Each pod can be fitted in five days, and this can be done at the end of the build.

'The principal worry with pod engines is the shock loading,' said Knight. Pod engines have not shown a great resistance to shock. The effect has been to move the shaft out of alignment within the pod so that it comes into contact with other parts of the engine, causing the bearings to fail. In the commercial market pod engines have used conventional roller bearings. To improve the shock resistance Knight has gone for sleeve bearings that offer greater and more constant contact within the bearing itself.

The pod structure and prop-blade will be built by Rolls-Royce and Alstom will supply the electrics. This will also be the first aircraft carrier to be fully electrically powered, which allows the designers to place the engines wherever they like. The generators, capable of 150MW, will be connected to the ship's systems by 2,000km of cable, which will have to be designed into the vessel.

Another consideration the designers must take into account is the Navy's difficulties in recruiting and retaining personnel. With this in mind Knight is aiming for a ship that needs the smallest crew possible. The US Nimitz-class carriers, at around 100,000 tons, are the giants of the sea and take a crew of about 5,000. Closer in size to the future carrier is the Charles De Gaulle at 45,000 tons with a crew of 2,000.

But Knight and his team are hoping to undercut this by automating as large a proportion of the heavily manned systems as possible. For example, in the original design the weapons-handling role was almost entirely automated. On a US carrier typically there are 250 people employed solely in handling weapons. Knight said he had got that number down to about 20, with roughly the same number of bombs to handle. However, some of the automatic systems will be lost in the cost trade-of process, he said. 'There will certainly be automation in some form. In the past evolution the magazine was fully automated. The preparation of the weapon was also semi-automated. We will now look at what is manpower intensive and what a robot could best do.'

Another uncertainty, which Knight must plan for, is the Joint Strike Fighter, the US short take-off and vertical landing aircraft, which the MoD plans to fly from the carrier.

The carrier is designed with a ramp to suit the STOVL jet, but the design includes space for a steam-driven catapult. This is primarily in case there is no STOVL jet to replace the JSF when it comes to the end of its 25-year service life, but Knight is not entirely confident that it won't be needed before then.

'You could say as well that we want to hedge our bets just in case the STOVL does not work. It is still a prototype. It has flown but as with all these projects weight grows, and we are nowhere near that point [when it will make its first take-off or landing from an aircraft carrier]. We are designing the ship as a STOVL ship with a ramp on the flight deck, but we can easily take the ramp off.'


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