Designing the Type 26 frigate

The Royal Navy is going through one of the most tumultuous periods in its entire illustrious, five-century existence. It’s a time of conflicting emotions as the old flagship, Ark Royal, is sent into history before its time, according to some commentators while new Type 45 destroyers take their first trip down the Clyde and into service. The submarine fleet is also being refreshed, with the new Astute-class attack boats on sea trials. And nobody could fail to notice the massive sections of the new flagship, Queen Elizabeth, arriving at the dockyard in Rosyth to be assembled, with yet another wave of controversy over its initial lack of aircraft-launching capability and, indeed, aircraft.

But the activity isn’t just confined to dockyards. Yet another of the navy’s ship classes is also approaching retirement, and this time it’s the Senior Service’s workhorse, the frigate fleet. Smaller and lighter than destroyers, the frigates referred to as Type 23s or occasionally Duke-class ships have been in service since the 1980s and are due to be decommissioned towards the end of this decade; three have recently been sold to the Chilean Navy. Although steel is as yet uncut on their replacements, which will be called Type 26s, the project to design the new backbone of the 21st-century Royal Navy is well under way.

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’The Type 23 frigates were designed in the late 1970s and early 1980s. They came into service from the late 1980s to 2001 and it was envisaged that they’d have an 18-year life,’ explained Brian Johnson of BAE Systems Surface Ships and director of the Type 26 project. ’That timescale was based on the fact that their primary role was antisubmarine warfare [ASW] and it was assumed that they’d spend most of their time sitting in the North Atlantic following Russian subs. But the world moved on and actually they’ve spent most of their lives in the Caribbean and the Middle East, in seas where the stresses on the hulls are much less than in the Atlantic.’

Because of this, the hulls are actually lasting about twice as long as originally envisaged. But after 35 years in service the last Type 23 came into service in 1999 and is scheduled to retire in 2034 they will reach the point where they can no longer be upgraded and new ships will be needed. ’If there isn’t a new ship coming into service if we don’t do this now then there won’t be a navy in the sense that we currently think of it, as a service that can patrol around the world.’

The project to replace the Type 23s (and their predecessors, the Type 22s, four of which are still in service) has, therefore, been in existence, in various forms, for some time. But with the absolute deadline approaching, it began in earnest last year. This is a complex procedure, as Johnson explained.

Frigates have a number of roles, with ASW at or near the top of the list. ’It’s massively important in several fronts of large-scale warfighting and it’s also needed to support the nuclear deterrent submarines you need to know where other submarines are,’ Johnson said. ’Within NATO, the Royal Navy is the undoubted ASW expert.’ However, the other roles are equally important and, in recent years, far more common. Type 23s are doing anti-piracy missions off the Horn of Africa and drug interdiction in the Caribbean; they are used for humanitarian missions and many other tasks not suited to the navy’s more specialist ships, such as minesweepers, amphibious landing ships and carriers. ’They do the bulk of the work of the day-to-day bluewater navy.’

To replace them, therefore, the first task was to figure out what the replacements would have to do. This is termed the ’requirement’ and is drawn up by a high-level group within the Ministry of Defence (MoD). ’It gets put together in broad terms of “we need a ship to do this”,’ Johnson said. ’It defines things such as how fast the ship will go with roughly what size of crew and what size the radar will be. That starts to give you an indication of the size of the ship, because radars are heavy and need to sit a certain distance above the sea.’ The requirement also sets how many ships will be needed, as the navy is sized to cope with one ’medium’ and two ’small’ conflicts at any time. The Iraq and Afghanistan campaigns are both classified as medium, which is why the navy has been overstretched for the last decade.

For Type 26, the requirement specifies eight ships capable of ASW and five ships equipped for more general duties. ’ASW ships have to be quiet,’ Johnson explained. This isn’t to prevent them from being discovered, but to make sure that the signals from the passive sonar system can be heard over the engines and the sound the ship makes moving through the water. ’So there’s a real design conundrum here. Do you make two completely different ships with different hull forms or one common platform that can do both, with different equipment on board?’

This, he said, was the subject of some discussion with the navy, resulting in a decision to build a common hull for both types of frigate, which can then be converted from ASW to general, or vice versa, in refit as required. ’People think that the cost of a warship is in the steel, because that’s what they can see,’ Johnson said. ’But actually it typically only comprises about five per cent of the cost. So although it seems like you’re buying something you don’t need, with five ships with stealthy hulls and no need for them, for the navy it’s actually much cheaper to have a platform that can do everything in terms of the through-life cost and the flexibility of the vessel. It’s the same as car manufacturers making a basic model that can actually have all of the available options on it if the customer ticks those boxes when they order it.’

Another feature that is likely to appear on the Type 26 is a ’mission bay’ at the aft end of the ship. ’This will allow us to use the ships as a base to launch small boats and, in future, autonomous marine vehicles,’ Johnson said. The ships will also feature a flight deck and hangar, most probably to house helicopters frigates currently on drug-interdiction duty in the Caribbean use helicopter patrols extensively.

BAE Systems won the contract for the assessment phase of the Type 26 project last year and is now approaching the important halfway point of the project, known as the Capability Decision Point and scheduled for November of this year. This marks the dividing line between the strict concept and design phases of the project. Currently, the team of around 200 engineers on the project is fine-tuning issues of the ships’ capabilities in a complex trading exercise, prioritising the various systems, fittings and functions on board in order to arrive at a description that fits the requirement but also comes in line with the budget for the project assigned by the government.

’The navy, of course, would love a ship that could do anything but that’s not affordable so we trade off certain capability and equipment to balance the cost and the relative advantage for the navy. At the decision point, we’ll present what we think is the best compromise to a very senior group within the MoD called the Surface Combatant Programme Board,’ Johnson said. This compromise will pin down the exact speed capability, the precise crew numbers, the calibre of its main gun and, just as importantly, what the ship will not be able to do. ’For the second part of the programme, we’ll do detailed design work to price it up accurately and at the end of the assessment exercise we’ll have a 3D CAD drawing that will show you exactly what the ship will look like and what will be there. That gets us to what’s called the main-gate decision point. At that point, we can start the planning of the build itself, purchasing some of the major pieces of equipment, and we’d cut metal maybe nine months to a year after that.’

Heading up the assessment exercise is chief engineer Steve Lewis, a veteran of the Type 45 project, who explained how the ’trading’ system works. ’In order to be able to trade, you need to define a reference point, which is the mid-point of the design options that we have.’ Johnson described the reference case as ’our best guess at what the committee is likely to accept’.

The engineers then look at the benefits and costs of each system on board, initially in isolation and then as a whole package. In some cases, for example, a system might have a low purchase cost, but its through-life costs would be high; a more expensive initial outlay might lead to lower maintenance costs and therefore a cheaper overall solution. ’You also trade off one thing against another. For example, do you value accommodation above propulsion? Are you prepared to have a more expensive engine system if it means the crew is less comfortable?’

This programme depends on having a good idea of how much things cost and that isn’t always easy. ’Where we think there’s significant risk in the pricing, either because it’s technology that we’re not familiar with or it’s a particularly high value, we’ve gone to the supply base, at various levels, with requests for quotation or information, or we’ve placed study contracts to generate price information,’ Lewis said. ’At the moment, the challenge is to hold the cost of the reference design down. When you do more engineering studies, you uncover issues with the project that generally add to the cost, rather than deleting from it.’

However, Lewis is certain that the way the project is being tackled will lead to a true reflection of how much it will eventually cost, even with the build phase of the programme running into the next few decades. ’The information underpinning our decisions, the robustness of the cost data and the detail with which we’ve looked for all the benefits associated with each option choice are being taken much further than with previous projects I’ve worked on, such as the Type 45 destroyers.’

Another difference from the destroyer project is that Type 26 represents a continuity of service duty, rather than a step change, according to Johnson. ’The Type 45 destroyer is an amazing warship,’ he said. ’But there was an awful lot of risk getting it into service because there’s so much new equipment on a new hull. We’re doing it much more progressively in the 26.’

For the first few Type 26s entering service, much of the equipment on board will be transferred from Type 23s as they go out of service. ’This is equipment that isn’t even on the 23s yet; it’s what we’re calling “future legacy”,’ Johnson explained. ’It means that the new hull will be a smaller step change in the frigate capability still a very significant one, but the systems will be common with the older hulls, which reduces the risk of the project.’

The team working on Type 26 at the moment is composed of fairly senior staff with a great deal of experience, Lewis said. ’We try to get more blue-sky people involved in this phase, to look for more innovative solutions than we’ve tried on previous projects. We had a parallel team looking at an export solution, thinking about how we’d design the ship if we didn’t have the constraints of working for the Royal Navy; we’ve now brought the two teams together and have come up with some new ways to drive costs down.’

As the project progresses, however, the make-up of the team will change. ’Some of the blue-sky thinkers will leave the team, but most of the people will stay involved and they have the background on why we decided on this set of solutions.’

The first of the Type 26 frigates isn’t scheduled to enter service until 2021, but they will be in the water in 2014, Johnson said. Although the project is a long-term one that will define much of the Royal Navy’s capabilities for the rest of the century, the pace is accelerating and its first fruits will be visible sooner than many people might expect.