Click to Enlarge. The Expeditionary Mobile Base USS Lewis B. Puller (ESB-3) operated in the Persian Gulf, March 5, 2021. US Navy photo.

The 100,000 Ton US Navy Ship That Iran Is Copying

The US Navy's gigantic Expeditionary Mobile Base (ESB) ships are among the largest naval vessels afloat. They are part of America's unrivalled global reach, but they are no longer unique. Iran is testing a similar Forward Base Ship which is comparable in size.

H I Sutton  11 Mar 2021

The U.S. Navy’s third Expeditionary Mobile Base (ESB), the USS Miguel Keith (ESB-5), is currently undergoing sea trials in San Diego. It is expected to be commissioned in May, when it will be one of the largest naval ships in the world. Although less well known, the ESBs are as large as super-carriers and can bring a massive amount of firepower to the game through the forces they directly support.
Few navies can even dream of such a capability. But the Iranian Navy is emulating these ESBs with their own form of forward base ships.

The US Navy’s use of floating Forward Bases is not entirely new. During the Tanker War of the 1980s Naval Special Warfare (NSW) units were based on barges stationed in the Persian Gulf. At the time they were dubbed Mobile Sea Bases (MSBs). What is much more recent is dedicated ocean-going ships which can act as forward bases all over the globe. These have much better facilities and, in particular, can support a sizable and diverse air capability. This can include V-22 Osprey transports and the US Army’s AH-64E Apache gunships. This is in addition to regular patrol boats, landing craft and Special Forces combatant craft.

Iranian Navy’s Forward Base Ship

The Iranian Navy’s own forward base ship is the I.R.I.N.S. Makran, a converted tanker (formerly Beta, IMO 9486910). The work was carried out over several months at the Shahid Darvishi yard near Bandar Abbas. Since being refloated in November 2020, she been on sea trials and exercises in the Straits of Hormuz and Arabian Sea. Where she will be based is open to speculation because she is much too large for most of Iran’s naval bases. For the moment she is still berthed adjacent to the Shahid Darvishi yard.

Makran is approaching the size of the U.S. Navy ships. Although accurate figures for her displacement are not available, it is likely in the same ballpark as the American ships making her among the largest navy ships of any nation. A large helipad has been added at the forward end with deck parking for several helicopters. The tanker already had a deck crane on rails which makes it ideal for handling small boats. This means that half the massive deck is given over to air operations, and the other half to boat operations.

US Navy and Iranian Forward Base Ships compared. Includes material © CNES 2021, Distribution Airbus DS all rights reserved / PLEIADES satellite imagery | Acquired through ShadowBreak Intl

Overall the new ship is less capable than its US counterpart, but not without a usefulness. It can operate any of Iran’s helicopters including the larger SH-3 Sea King and CH-53 Sea Stallion types. It also carries a wide range of small boats, particularly related to Iranian’s Marine Brigades. These have included the Al-Sabehat 15 SDVs (Swimmer Delivery Vehicles) used by the Iranian SBS (Special Boat Squadron) to support amphibious operations.

The IRGC’s Alternative Approach

Iran’s other navy, the IRGC-N (Islamic Revolutionary Guard Corp – Navy), has also acquired Forward Base ships. The Saviz, ostensibly still a civilian merchant ship, has been deployed to the Red Sea for several years. She carries small boats and may be involved in intelligence gathering as well as general support of Houthi forces in Yemen.

Recently the IRGC-N also commissioned a declared (Saviz is undeclared) forward base ship, the I.R.I.S. Shahid-Roudaki. This ship is smaller, less than half the length of the U.S. Navy ships and about a ninth of the displacement. But her fit includes anti-ship (or possibly limited land attack) cruise missiles. The IRGC has showcased her ability to deploy drones as well as helicopters. They have also parked a 3rd Khordad anti-aircraft missile system on the deck. Its usefulness is open to challenge and recent imagery shared by The Intel Lab shows that it is not a permanent fixture. They have also pulled boats aboard although there are only limited facilities to launch them.

Overall the U.S. Navy’s ESBs are still the standard that other navies can aspire to. But it is interesting that Iran is the first country to try to emulate the capability, albeit in their own flavor.