상륙정 신형 LCAC (Ship to Shore Connector, LCAC 100)이 미해군에 배치

[위종민]

https://news.usni.org/2022/02/14/video-first-new-navy-hovercrafts-deliver-to-fleet-unit-after-delays-cost-increases

신형 LCAC-100급 (Ship-to-Shore Connector) 1, 2번함인 LCAC-101과 LCAC-102가 미해군에 인도돼 제4강습정부대(Assault Craft Unit 4)에 구형 LCAC와 함께 혼성편성됐습니다. 이 1, 2번함은 미해군의 Ship to Shore 개념의 일부이며, 본격적으로 상륙함대에 배치되기 전 각종 시험을 실시할 예정입니다. 

이 LCAC는 원래 2018년 7월 인도될 예정이었지만, 더 강력해진 엔진과 두 개의 추진용 팬을 구동하는 복합 드라이브트레인과 관련된 개발지연으로 기한이 연장됐습니다. 개발사인 텍스트론이 신형 드라이브트레인과 롤스로이스 가스터빈 엔진을 통합하는 게 난관이었다고 하네요. 비용또한 올라가 척당 단가가 2011회계년도 기준 5370만 달러에서 6370만 달러로 올랐다고 합니다. 

미해군과 육군은 베트남전에서 공격용 호버크래프트를 시험했었으나, 미해군과 해병대는 곧 호버크래프트가 상륙함과 해안을 연결하는 데 유용하다는 데 주목해 LCAC를 개발했습니다. LCAC는 탱크나 야포같은 중장비를 상륙함의 광대한 차량적재구역에서 별다른 인프라 구축 없이 해두보로 직접 나르는 게 가능했습니다. 

2001년 미해군에 LCAC 배치가 완료된 후, 기존 LCAC보다 승조원을 줄이고 유지보수가 편하며 적재량을 늘리는 것을 목표로 Ship to Shore 프로그램이 시작됐습니다. 해병대에 배치되는 장비들의 무게가 무거워짐에 따라 - 일례로 NSM 발사기를 실은 JLTV는 기존 동급 차량보다 무거움 - 적재량 증가가 요구돼, 신형 LCAC는 지뢰처리장치를 탑재한 M1A1을 탑재할 수 있도록 중량 75톤, 최고속도 35노트를 발휘할 수 있게 설계됐습니다. 

그러나 텍스트론과 초도생산 계약을 체결한 후, 미해병대는 대규모 강습상륙작전 대신 태평양의 섬 뜀뛰기 전술에 집중하며 전차를 모두 없애버렸습니다. 이제 이 신형 LCAC를 미해병대의 Force Design 2030에 맞춰 운용하도록 운용방안을 마련해야 합니다. 

또한 새로 탑재된 오토파일럿 시스템으로 LCAC를 다루기가 더 편해졌다고 합니다. 

VIDEO: First New Navy Hovercrafts Deliver to Fleet Unit After Delays, Cost Increases - USNI News

February 14, 2022 10:58 PM

JOINT EXPEDITIONARY BASE LITTLE CREEK – FORT STORY, Va. – Two Navy hovercrafts glinted silver in the low Friday sun as they cut across the Chesapeake Bay, blasting a wake of mist 25 feet high as they headed to their new home.

Landing Craft Air Cushion 101 and 102 left the well deck of USS Carter Hall (LSD-50) to join the older LCACs of Assault Craft Unit 4. LCAC 101 and 102 are part of the Navy’s Ship to Shore and enter a testing regime before the new Textron-built craft join the Navy’s amphibious fleets.

“The real focus now for these craft and to deliver here to ACU 4 is to put them in the operator’s hands and allow those to be testing and training assets for their folks, getting sailors trained on how to operate these craft. And as we start bringing more craft they want to have the crews ready to go, so it’s a little bit of a handoff back and forth,” Capt. Scott Searles, the program manager for PMS 317 that oversees the amphibious assault ships and connector programs, said on Friday.

The two hovercraft arrived three years later than scheduled due to a string of developmental delays and cost overruns for the hovercraft program.

The Navy had originally planned for the first two LCAC 100s to deliver by the fall of 2018, but the program suffered developmental delays in part due to difficulties around the new propulsion system that used a more powerful engine and composite drivetrain to power the two massive fans that propel the LCACs, according to the Pentagon’s weapons testers.

Last year, the program tripped the Nunn-McCurdy law that calls for congressional notification for cost increases of more than 15 percent of a contract, but not to the 25 percent mark that requires Pentagon leadership to re-certify the need for the program. The costs rose from $53.7 million in Fiscal Year 2011 dollars per craft – a figure that included research and development costs – to $63.7 million in FY ’11, prompting the notification. 

“The [March 26] breach is attributed to first-in-class challenges that led to increased construction costs resulting from labor and material cost growth and schedule-related issues on early craft,” the service said in a statement to Defense News. “This is not a critical Nunn-McCurdy breach that would require recertification of the program, and [the undersecretary of defense for acquisition and sustainment] has been notified. The SSC program production is now stable as the first in class challenges have been resolved.”

Leading up to the breach, the service and contractor Textron had struggled with integrating the new drive train and Rolls Royce gas turbines that power the massive fans at the aft of the LCACs, according to Pentagon weapon testers.

Regardless of the setbacks, the Navy says it needs to replace the existing LCACs.

“The new craft is extending our ability to conduct operations, the current fleet of craft has reached almost reached their service life expectancy,” said Capt. Tony DeFrias, commander of Assault Craft Unit 4 on Friday.

Developed in the late 1970s and deployed in the late 1980s, the Landing Craft Air Cushion was key to how the Marines envisioned amphibious assault in the late 20th century. The Army and the Navy experimented with attack hovercraft during the Vietnam War with mixed results. However, the Navy and Marines saw value in craft that can connect ships to the shore. The concept called for LCACs flowing in heavy equipment – like tanks and artillery from the massive vehicle stowage areas on the Navy’s amphibious warships, without the need for port infrastructure – to secured beaches.

The Ship to Shore Connector program was developed after the last LCAC delivered to the Navy in 2001 as a refinement of the original concept that would take fewer sailors to operate the platform, be easier to maintain and carry more tonnage.

“Marine Corps craft, wheeled vehicles and everything have gotten heavier over the years. And so, it’s really important that these new crafts have the ability to carry more payload. And so that’s one of the other great things is we put more power into the craft and they can carry more now,” Searles said.

For example, the Marines Corps’ Joint Light Tactical Vehicle and emerging Naval Strike Missile launchers built on the JLTV chassis are much heavier than the existing crop of vehicles.

At the upper end, the new LCAC 100s were designed to move a Marine M1A1 main battle tank with a mine clearance sled to shore – about 75 tons – at 35 knots or faster.

However, since the initial contract with builder Textron, the Marines have shed their tanks in favor of a strategy that focuses on Pacific island-hopping rather than a massed amphibious assault.

“The Marine Corps is shifting to the Pacific, they want to, you know, change their concept of operations. They’re focused on standing up the Marine Littoral Regiment, putting a lot of time and energy into the Expeditionary Advanced Base Operations concept,” Searles said.
“We operate out of well deck and we carry Marine, we help the Marine Corps maneuver that and that mission is unchanging. It’s an enduring requirement. … We need both we need the Marine Littoral Regiments, and we need the enduring Marine Corps mission.”

The unit is set to deploy later this year and will be working to refine the LCACs’ role in the Marines Corps’ new Force Design 2030, DeFrias said.

“We’re working on those developing concepts and operationalizing them and these crafts will play a huge role in that in the movement ashore,” he said.

For the operators, the new LCAC-100s make the job of maneuvering the difficult to handle the hovercraft more manageable.

“The autopilot system on this thing is amazing. I could say it was probably designed towards a more of an autonomous-type vehicle,” Senior Chief Rafael Fana, who piloted one of the LCACs onto ACU-4’s flight line, told USNI News on Friday.
“These are monster machines.”