The exact dates of the departure of HMS Queen Elizabeth for sea trials and her subsequent arrival in Portsmouth have been subject of intense media speculation. Briefings last year had given the impression that sea trials would probably be conducted in March 2017, although many journalists overlooked the caveat that timings maybe subject to change. It is now clear that the sea trials date has slipped slightly but disappointment over minor delays must be seen in the context of a very ambitious 8-year building project. There have also been various other rumours about the project circulating, some of which are addressed here.
At the time of writing HMS Queen Elizabeth is alongside in Rosyth and well into the ‘test and commissioning’ phase of her construction. This includes the trials and integration of many systems. As the first ship of her class, she is effectively a prototype and much of her equipment is either entirely new, unique or has never been fitted in RN vessels before. As testing is conducted, a multitude of technical challenges have to be addressed and no one can say with absolute certainty when this process will be complete. The good news is that the Aircraft Carrier Alliance (ACA) confirm they have not discovered a ‘show stopper” or any specific serious problem could cause a major delay.
The ACA contract with the MoD stipulates that the ship must be handed over to the Royal Navy by the end of 2017 so, contrary to received wisdom, the project remains on schedule.
Overall there is great confidence amongst the builders and Ship’s Staff in Rosyth that the ship is sound, will meet its specification and perform well at sea. It is a virtual certainty that the ship will go on trials this summer and be delivered to the RN before the end of the year.
The sea trials programme
‘Spring sea trials’ will now be ‘summer sea trials’ but this is not cause for great concern. Considering the size and nature of the project, those involved should be congratulated on the relatively smooth progress that has already been made. The Ship’s Company is now working on board 24/7 and the ‘Ships Staff Move On Board’ (SSMOB) date is not far off. She is already transforming from a building site into something more like a warship. Safety and the operational readiness of the ship are the top priority of the contractor who remain the owners of the ship until she is formally handed over to the RN. It is obviously sensible to wait until they are fully confident in her before they declare the Ready For Sea Date (RFSD). The ‘delay’ maybe frustrating for government, the navy and the ship’s company especially, who would all like to get the ship to sea as soon as possible. Common sense dictates it would be unwise to rush departure, merely for political convenience or to meet an arbitrary deadline. HMS Queen Elizabeth will be under an intense media spotlight from the moment she puts to sea. Eliminating as many technical issues as possible while still alongside in Rosyth, before departure is wise.
Real cause for anger about delays should be directed towards the government of Gordon Brown which deliberately delayed the project in 2008 by two years for a short-term ‘cost saving’. Apart from extending the gap David Cameron then created in RN carrier capability, this eventually added around £1.5Bn to the total cost of the project.
The exact timing of sea trials for this mighty ship will be dependant on several factors. Departure from Rosyth is only possible under certain tidal conditions and there are several weeks between ‘tidal windows’. Manoeuvring a 70,000 ton ship out of the basin and through a very narrow lock cannot be done in high winds. Once she has left the river Forth, it is not intended that she will return to Rosyth. Like the whole test and commissioning phase, the sea trials schedule is only an outline plan and subject to change. The trials phase will be conducted in the North Sea and at the halfway point, the ship may use the deepwater berths at Invergordon or anchor in the Cromarty Firth.
“The QE Class programme represents an engineering challenge of unprecedented scale and complexity for UK shipbuilding. HMS Queen Elizabeth is at a mature stage of the testing and commissioning phase, which is designed to thoroughly assess her vast and complex systems and identify any requirements for further work in advance sea trials. We remain focused on delivering this critical capability for the Nation. HMS QUEEN ELIZABETH will undertake her sea trials programme in the summer of 2017.” Aircraft Carrier Alliance spokesperson.
Landing craft will not be carried
As the Queen Elizabeth Class (QEC) will also have to undertake the role of amphibious assault ship, many commentators have assumed that one, or both of the ships will be fitted to carry small landing craft (LCVPs). This is not the case and there is no provision for the carriers to embark LCVPs, CB90s (fast assault craft) or Hovercraft. Troops will essentially have to be transported helicopter (or possibly Osprey tiltrotor). For more detail see previous post. There is a small platform at the stern of the ship, colloquiality referred to as the ‘wodge’, which offers the option of loading and unloading personnel and equipment onto other small craft, mexeflotes etc. in benign weather conditions.
The original design has always included space for two Passenger Transfer Craft (PTC) and RIBs which will be accommodated and deployed from sponsons. As many ports will not be able to accommodate the ship alongside, she will often have to anchor offshore. Fast and safe transport for the ship’s company and visitors is an important requirement. The first of the PTCs has already been delivered by Alnmaritec Ltd, and with a nice nod to Fleet Air Arm history, is named “Swordfish”. She is highly manoeuvrable, can make up to 18 knots, has a crew of 2 and can carry up to 36 passengers. The seats can be removed so bulky items could be carried. The cabin area is heated and there is a set of heads forward.
Confidence in automation
In order to reduce the personnel requirement, the QEC are fitted with a Highly Mechanised Weapons Handling System (HMWHS) to transport ammunition and stores around the ship. Manned by around only 50 people, it can be operated with as few as 12 in an emergency. Similar to many systems already in use in warehouses and airports, loads are palletised to a standard size. FIAM (Flight In Air Material – eg bombs or missiles) come in many shapes, sizes and weights but this palletised rail system has the flexibility to quickly move all types. Sophisticated, but largely unseen capability such as this, allows aircraft to be readied quickly and maintain a high sortie rate. There has been some concern that automated systems like this are vulnerable to action damage or failure on extended operations. With a small Ship’s Company there would be few sailors available to make repairs or move loads using more manual methods. However HMWHS has been thoroughly de-risked on land-based test rigs, and there is confidence that it is sufficiently robust and reliable.
The QEC incorporates advanced magazine design to reduce the risk of fire and detonation of stored ammunition or fuel. There are dog-legs in delivery routes and measures to reduce the effects of flash and blast. One of the cost drivers and time-consuming aspects of any good warship design is to ensure it is properly battle-hardened and this is the case with the QEC. In the event of equipment failure or damage, there are work-arounds and back-ups to maintain a measure of fighting capability.
Structural concerns unfounded
A press report that suggested HMS Queen Elizabeth would suffer hull distortion from ‘hogging’ and ‘sagging’ is entirely unfounded. (Hogging is caused by the movement of waves which push up on the centre of the hull, causing the upper deck to bend down at each end, sagging is the opposite effect) This phenomenon affects all ships and is a foundational concern for any naval architect. At the design stage many hours were devoted to computer modelling the dynamic structural stress and deflections that would affect the QEC hull. The greatest stress caused by movement through large seas occurs around the aircraft lift openings at flight deck level. This has been addressed with major reinforcement and curves where it is cut out from the deck. A very experienced team spent several years designing the QEC and there is no reason at all to have any doubts about the structural integrity of a ship intended to last up to 50 years.
The QEC has two deck-edge lifts capable of moving two armed F-35s (or even the entire ships company!) simultaneously. They have been designed and manufactured by MacTaggart Scott, probably the world leaders in aircraft lift design, drawing on long experience with many other carriers. The QEC lifts avoid the many engineering problems encountered with the centre line ‘scissor lifts’ employed on the Invincible class.
IEP propulsion – like the type 45, but not like the Type 45
The QEC and the Type 45 destroyers both use Integrated Electric Propulsion (IEP) There are no direct drives from either Diesels or Gas Turbines wich provide electricity to the main propulsion motors. Sophisticated Variable Frequency Variable Power (VFVP) technology is used to control speed. That is where the similarities end. BAE Systems designed the Type 45 althought the MoD made the key propulsion decisions. A specially recruited Thales team designed the QEC. The QEC are designed to cruise on diesels with their MT-30 gas turbines brought online for higher speeds. The Type 45 was designed to cruise on its supposedly very efficient WR-21 Gas turbines, and only use diesels for extra speed. Unfortunately the intercooler-recuperators fitted to the Type 45 gas turbines have proved problematic. The MT-30s used by the QEC have been well tested and is a simpler, more reliable option.
QEC has duplicated main and secondary machinery in two well-separated complexes with independent uptakes and downtakes in the two islands. From a propulsion perspective, the QEC is like two ships. If the forward system is damaged, the after section will keep going and vice-versa, another reassuring aspect of a resilient design.
Although there are some aspects of the QEC project that are cause for concern, her designers and builders should be commended for an incredible British achievement. After years of anticipation, we can look forward HMS Queen Elizabeth putting to sea in the summer and a world class warship being delivered to the Royal Navy in 2017.
*Technically, as she is not yet in commission, the ship should not be called “HMS Queen Elizabeth”. However dropping the ‘HMS’ prefix is likely to cause unfortunate confusion with the reigning monarch.
- Technical Issues Behind HMS Queen Elizabeth ‘Delays’ (Forces TV)
- Why your CVF should not moonlight as your LPH (Save the Royal Navy)
- When will HMS Queen Elizabeth arrive in Portsmouth (Save the Royal Navy, Oct 2016)
- Swordfish Passenger Transport Boat – Video (Alnmaritec)
- Highly Mechanised Weapon Handling (Ship Design Blog)
from Save the Royal Navy http://www.savetheroyalnavy.org/hms-queen-elizabeth-making-good-progress/