LOTS to deliver: Singapore Technologies Marine unveils Endurance 160 helicopter support ship

Singaporean naval yard Singapore Technologies Marine (ST Marine) has unveiled a new variant of its Endurance-class Landing Platform Dock (LPD).

Dubbed the Endurance 160, the 14,500 tonne warship is the first one designed by ST Marine with a full length flight deck.

The length overall is quoted as 163.7m, with the flight deck estimated at around 146m long by 25.6m wide with five deck landing spots.

Endurance 160 drawings provided by ST Marine appear to show two deck elevators. One is sited on the starboard side forward and the other amidships close to the aft end of the island superstructure.

The island is of a blockhouse design with a single mast and funnel and two levels. The flight control station is aft of the island.

The complement is quoted as 140 personnel, with another 150 for its air wing. Troop capacity is given as 400 troops.

It is noteworthy that the new class of warship has a quoted top speed of 22 knots - five knots better than the quoted 17 kts top speed for its Endurance 140 cousin. Max range is mentioned as "more than 7,000 nautical miles" when sailing at 15 kts.

Gun armament options on the foc'sle and stern quarter are presumed to be indicative of customer options for placing medium calibre guns and close-in weapon systems (CIWS). The weapon stations do not appear to require deck penetration.

It is not known if the Endurance 160 will offer bow doors, as seen on the 141-metre long Endurance 140 class. The 22 kts max speed of this class probably excludes bow doors as such a feature and the associated ramp would weaken the forward end of the ship.

It also remains to be seen if the new Endurance variant can carry floating pontoons strapped to the side of its hull. These self-propelled pontoons are used to discharge vehicles and troops during logistics-over-the-shore (LOTS) operations.

The design draws heavily upon the Republic of Singapore Navy's (RSN) experience with its four 141-metre long Endurance-class tank landing ships (LST), which, interestingly, have been referred to by at least three standard naval designations.

The Endurance ships were introduced in 1998 as LSTs but referred to by naval authorities as Landing Platform Docks (LPD) as they have a well dock aft for four Fast Craft Utility water-jet propelled landing craft.

During Operation Flying Eagle (OFE), the Boxing Day tsunami relief mission off Sumatra in Dec 2004/Jan 2005, three Endurance ships deployed for the Humanitarian Assistance and Disaster Relief mission were referred to as Helicopter Support Ships.

Tonne for tonne, ST Marine's Endurance 140 design can carry more landing craft than any other LST/LPD design available today. The mothership can land a battalion-size team in one wave using its onboard FCUs and Fast Craft Equipment Personnel (FCEP) landing craft.

Each Endurance 160 is designed to carry two FCU-type landing craft and a pair of smaller FCEPs. It is likely that the landing craft complement will include the new drive-thru design, which ST Marine designed specifically for LOTS operations involving main battle tanks, which could include but are not limited to Leopard 2-type MBTs.

The Endurance 140 cannot operate hovercraft as the well dock is not heat-shielded from jet blasts. It will be interesting to see if the enlarged Endurance with the full flight deck will have a protected well dock for hovercraft.

The Singaporean Navy's experience off Sumatra showed that the Endurance-class ships are more versatile than former East German Navy Frosch-class LSTs operated by the Indonesian Navy. The Frosch-class LSTs were designed to discharge vehicles, personnel and deck cargo by direct beach assault in the Baltic area and European coastlines and do not carry their own landing craft.

In addition to small craft, the Endurance LSTs are the RSN's first ships that can embark a CH-47D Chinook on its flight deck. The ship can operate two Super Puma-type helos simultaneously, or one Chinook.

The Singapore Armed Forces (SAF) has been deployed as part of a multinational task force for counter-piracy operations in the Gulf of Aden. These missions were spearheaded by Endurance-class warships, equipped with two Super Puma/Cougar type choppers as part of its air element.

The Endurance 160's designers may want to relook the design and operation of WW2 escort carriers for takeaways.

Specifically:

* Deck edge lifts would allow out-size helos to manoeuvre into the hangar bay. United States Navy LPHs and the Spanish Navy helicopter carrier (which was derived from Admiral Zumwalt's Sea Control Ship design) all have a deck elevator at the stern which allows rapid movement of helos from hangar to flight deck.

* Loading the Endurance 160 with landing craft and naval aviation assets in a hull of that size means operational compromises. Is the ship meant to operate close inshore, close to the surf zone of a contested coastline so it can deploy landing craft expediently, or is it meant to lurk farther offshore and hit the zone of operations using its embarked air wing?

* Going by the Endurance 140 design, it does not appear that the Endurance 160 will have sufficient hangar space for helos to be struck down for all-weather protection. It thus appears the air wing will be embarked for short duration missions to its area of operations before withdrawing back to base. In the case of a peacetime HADR mission, the vehicle deck would presumably not be filled with war material and some space would probably be reserved for helo maintenance.

* The closest design to the Endurance 160 is the Italian Navy's 133-metre long San Giorgio-class LPDs, a mid-80s era design. The RSN encountered the San Giorgio-class in the Persian Gulf during Operation Blue Orchid 1 and came away impressed with the capabilities packed into the compact hull form.

* The onboard armament will need to be upsized if the ship is to fight and survive against enemy frigates, missile-armed small craft and SSKs. As an interesting aside, notice the number of GPMGs added to the bow of an Endurance-class LST sent for duty in the Persian Gulf. Incidentally, the bow was a popular spot for smokers during the OFE mission.

* An enclosed hurricane bow may result in a drier flight deck in heavy seas. Early escort carrier designs which were converted from merchant ship designs had open bows which could not keep out a green sea.