The September 2009 issue of Proceedings is topic centric to Naval Aviation, and there are several naval aviation articles in the issue that are very good. However, I want to discuss the subscription only LCS article written by Milan Vego included in this months issue. It covers a number of LCS issues from history to current situation with module challenges ahead, but as the title hints (the topic of the article is No Need for High Speed), the LCS speed issue is addressed squarely.
High speed for a surface combatant generally incurs much higher construction costs, power requirements, fuel consumption, and maintenance; and decreased range, payload, and stealth. Yet the Navy’s specifications required the LCS to achieve a full speed of 47 to 50 knots. Normally, the high-speed requirement is based on the ship’s size, primary missions, and prospective operating environment…
Because of the speed requirement, the useful space for weapons and sensors is only about 400 tons. After deducting the needs for fuel, ammunition, crew, and stores, some 180 tons of payload remain for the mission packages.
This article is nearly 2400 words, so I am not attempting to capture the greater quality present in the article, rather examine options available for the LCS the designs.
Bob Work released a report for CSBA (PDF) during the Presidential transition period that emphasized the Littoral Combat Ship from a point of view of innovation, suggesting block purchases be used to develop the design from the current starting position. Frank Hoffman released a report for CNAS (PDF) during the same Presidential transition period that also highlighted the need for innovations in littoral warfare. This isn’t trivial, Bob Work is Undersecretary of the Navy now, and Frank Hoffman is now working out of Bob Works office. That would suggest the civilian side of the Navy is looking at the two initial LCS designs as a starting place, not a conclusion.
Milan Vego’s article stresses that the high costs of the initial LCS hulls are a result of the emphasis on speed in the design of both ships; and he also suggests that emphasis directly influences design decisions that impact power requirements, fuel consumption, maintenance, endurance, and payload. Everything from the materials used to the specific detail design is influenced by the speed requirement, so if the LCS requirement for speed is reduced, my first question would be how much redesign is even possible? What would the LCS trade speed for?
Assuming the hull forms do not change significantly, the size and available space of the ships are unlikely to change. That means speed would be traded for either endurance or weight, perhaps a little of both. Maximum speed, cruising speed, and endurance are all factors primarily determined by the diesel and turbine engines, which raises the question whether change would require a redesign of the power plants. Could hull design changes, absent large scale power plant adjustments, significantly influence cruising speed on diesels? Absent the speed requirement, would there be significant cost reductions in LCS construction? I am unsure; I tend to think the costs will simply be spread around and savings will be minimal, but smart shipbuilders have suggested to me in the past that significant costs could be saved per hull by simply dropping the speed requirement.
If Milan Vego is right regarding the costs of speed, how does the Navy justify the increased costs? The Navy has a responsibility to the taxpayer to be a good steward of money spent for the fleet. How much of the LCS construction cost is a result of speed? 1/3? 1/4? 1/5? What about operational costs? What do logistics models look like with a cruising range of 4000nm? What about 6000nm? The Coast Guards Bertholf class has a 12,000nm range. What compelling warfighting argument suggests very high speed is ‘worth’ the investment?
The DDG-1000 was truncated for reasons of costs, likely in part due to the stealth design requirement in particular which increased the cost of existing large surface combatants by around 25%, because stealth required a much larger hull. I do wonder if the LCS cost is 25% higher because of the speed requirement. Both ships were over budget by several hundred million dollars, how much of the cost increase is a result of design considerations that must factor the speed requirement?
25% seems like a high estimate, but very smart people have suggested it may in fact be very close to the truth. Why would that extra cost for speed be excused? In the LCS program, the speed requirement could potentially be increasing the program costs by more than $7.5 billion over 55 hulls, and the operational cost increases as a result of the speed requirement won’t be insignificant.