Upgrades to the Scottish facility used to ammunition the Royal Navy’s aircraft carriers

The MoD is about start work on a major upgrade of the Northern Ammunition Jetty in on Loch Long in order to enable the Queen Elizabeth class (QEC) aircraft carriers to load and unload ordnance. Here we look at the jetty project in detail.

In an extremis it is would be possible for the QEC to be fully stored for war at their home base of Portsmouth. However, the Upper Harbour Ammunition Facility (UHAF) used by other warships is too small and handling explosives alongside in the dockyard is avoided under most circumstances. Although DM Gosport is close by, the key facility for dealing with the UK complex weapons inventory, including F-35 weapons, is at DM Beith in Scotland. Glen Mallen on Loch Long will, therefore, continue to be the site where RN aircraft carriers will load and unload the majority of their ammunition. This facility, known officially as the Northern Ammunition Jetty, was built in 1958, the most recent upgrade was completed in the 1970s. It has been used by RN and RFA vessels for many years but without remedial work would become unsafe the next 10-15 years.

Loch Long is steep-sided, relatively narrow but very deep and can accommodate large vessels with careful navigation. There is another ammunition facility at Crombie on the Firth of Forth but it appears it has not been chosen to support the QEC as it requires transits under the Forth bridges within time-constrained tidal windows. Glen Mallen also benefits from being supplied from nearby DM Glen Douglas which is the largest weapons storage site in Western Europe and has the capacity to handle the high volume of ordnance required by the QEC.


This is the outline design for the new jetty based on information made public for planning consultation purposes and the actual construction may be subject to minor modification.

To accommodate the much larger QEC the old jetty and piles are being demolished entirely and replaced with a new platform built from scratch which can support a vessel twice the size of the existing facility. The new jetty will have a reinforced concrete deck supported by 200 piles. Five new mooring dolphins will be connected to the jetty by pedestrian access bridges. To ensure the QEC can be securely berthed, to resist tidal movement and hurricane-force winds that may occasionally be experienced in the area requires at least 14 separate mooring lines and springs. Head and stern lines need to be secured at an oblique angle to the ship to reduce strain on them and this necessitates the mooring dolphins that extend beyond the jetty.

Modern pedestal cranes will be installed and new pre-fabricated modular buildings for offices, stores, fuel store, back-up generators and switchgear will be built. The site will be protected by new fencing, a CCTV system and lighting masts. Two 6m high towers for navigation lights will be installed on the new jetty itself but a further four navigational aids will be required either side of Loch Long placed on towers in the water. Work on the £52M project is scheduled to begin shortly and will take around 2 years with completion due in the summer of 2021. The majority of construction material and waste will be transported by barge with minimal disruption to the public. The new jetty is intended to have a 50-year design life, similar to the QEC ships and last into the 2070s.

  • Basic rendering of the new jetty at Glen Mallen.

  • Simplified chart showing the four new navigational aids that will be installed to guide the QEC up the narrow Loch.

  • View looking east showing how the jetty is connected with DM Glen Douglas where weapons are stored and prepared for issue. (Image: Google/DigitalGlobe)

  • DM Glen Douglas looking West. The road/rail transfer point can be seen bottom right while the service road to Glen Mallen Jetty can just be seen emerging from the trees (top right). The 56 storage bunkers with a total capacity of 40,000 cubic metres of munitions are dispersed around the hillsides. (Image: Google/DigitalGlobe)

  • HMS Ark Royal Glen Mallen

    HMS Ark Royal leaving Glen Mallen in January 2003 after receiving a full outfit of weapons in preparation for her role as RN flagship for Operation Telic, the invasion of Iraq.

  • HMS Illustrious Gen Douglas Ammunition Jetty

    HMS Illustrious embarks ammunition prior to exercise Cold Response in Norway, February 2012.

  • HMS Ocean Glen Mallen 2015

    HMS Ocean takes on ammunition at Glen Mallen after her 2015 refit.

It is estimated it will take three days to load or unload the QEC with a complete outfit of munitions, but this evolution would only happen about every three years for each ship. With two carriers in service, this process will take place on average about once every 18 months and the main public road will be closed as a safety precaution during that time. Considering the large munition requirements of potentially up to 40-50 aircraft, three days to complete this work illustrates the great efficiency of the modern weapons handling systems of the QEC design (to be discussed in more detail in a future article). The operation to transport and prepare what will be hundreds of pieces of ordnance at the Defence Munitions sites beforehand must be many weeks of work. Once fully operational, the carriers will retain much of their munitions outfit safely stowed in their deep magazines for up to three years at a time and only fully de-ammunition prior to refit periods. To maintain their Lloyds Certification, after the initial dry docking inspection (recently completed by HMS Queen Elizabeth) dry docking is then expected to be carried out about once every six years probably as part of a major refit package.

The work at Glen Mallen is just one of several DIO (Defence Infrastructure Organisation) upgrades to naval Jetties, partly prompted by the needs of the aircraft carriers, but to the benefit of the navy as a whole. Bedenham Jetty which is used to deliver ammunition from DM Gosport to warships at the UHAF in Portsmouth also being rebuilt and having new cranes in a £36M project. The Oil and Fuel Jetty at Gosport is having a £30M refurbishment. Work on a £43M replacement for Yonderberry Oil and Fuel Jetty at Torpoint is well underway and should be completed this year.

It is important to note further defence infrastructure investment being literally put into the ground in Scotland, counter to nationalist claims that Scotland somehow gets a ‘raw deal’ in the division of defence spending. Brexit has given new impetus for demands for an independent Scotland which is an existential threat to the Royal Navy in particular (and by implication the security of everyone in the United Kingdom). Besides the obviously critical Faslane/Coulport facilities and Clyde shipbuilding, the logistic and support chain for the carriers is heavily dependent on DM Beith, DM Glen Douglas and Rosyth. There is continued expenditure on existing, and often ideal, Scottish facilities, for example at Faslane, RAF Lossiemouth and this modest project at Glen Mallen, but with no apparent ‘Plan B’ in the event of independence.