[This article was first published in Army Sustainment Professional Bulletin, which was then called Army Logistician, volume 2, number 2 (March–April 1970), pages 16–22.]
A SUBSTANTIAL NUMBER of big, fast ships of unmatched productivity will be added to the U.S. merchant marine during the next few years. To permit effective use of these ships for support of emergency deployments under current strategic concepts, the Army's contingency terminal systems will have to be modernized.
Lighterage and Rapid Deployment Strategy
Today's strategic planning calls for deployment of major forces within a few days across the breadth of the world. Strategic transport aircraft are able and ready to deliver spearhead units and the troops of follow-on forces, but the equipment for heavy forces and sustaining supplies must follow by sea. Over 97 percent of Vietnam supplies and equipment has been transported by sea, notwithstanding the extensive airlift provided during the last four years.
Operation of a sea resupply line depends upon effective far-shore terminal operations, and terminal operating units must be among the first elements to reach the objective area in a contingency buildup. Terminal service companies and their equipment can be moved rapidly by air and ship, and lighterage crews can be moved by air, but deployment of lighterage to handle heavy resupply tonnages is another matter.
During the Vietnam buildup period, every possible method of transporting floating craft was exploited. Nevertheless, lighterage deployment was spread over more than a year. Although combat units and logistics operating personnel can be positioned in an objective area within a few days, the design of today's floating craft and of the ships available to move them overseas does not provide a matching capability for heavy lighterage equipment.
Approaches to Lighterage Deployability
In the future the deployability or lighterage can be made to equal that of combat forces by three general approaches: equipment can be redesigned for transport on the kinds of ships which will be generally available in the future U.S. merchant fleet; new kinds of specialized ships can be relied upon for lighterage movement; or lighterage can be built to be self-deliverable to overseas areas.
Modern pontoon equipment could satisfy the first approach. During the last year, the Army has evaluated the MEXEFLOTE pontoon equipment developed by the British Army. The "can barges" of World War II and Korea, which are still in inventory in large numbers, require assembly on ways or at shore locations equipped with heavy cranes that can lift the assembled barges into the water. From assembly locations, the barges must be towed to the operating area. MEXEFLOTE pontoons, in contrast, can be assembled rapidly in open water at the side of the delivering cargo ship. A 15,000-measurement ton container ship could deliver enough pontoons to make barges with a load capacity of around 4,000 long tons, a substantial operating capability. A system of this kind is a prime candidate for initial support operations, although its potential as a general lighterage system is constrained by limited seakeeping ability in heavy weather, limited range for coastal operations, and relatively small capacity.
Barge-carrying ships, which began to enter service in 1969, offer a second possible system for delivering lighterage rapidly to oversea operating areas. LASH (Lighter-Aboard-Ship type, being built for Prudential Lines and Pacific Far East Lines) ships will transport barges designed specifically to fit their holds. These, however, do not appear adaptable to movement of a variety of craft, whereas SEABEE (Sea barge carriers under construction for Lykes Brothers Steamship Co., Inc.) types promise to be excellent multipurpose ships. The SEABEE carries thirty-eight 850 deadweight ton SEABEE barges. A 2,000-long-ton-capacity stern elevator lifts two barges at a time to one or three deck levels where a transporter moves the barges forward to their operating positions. The ship can handle a wide variety of floating craft, ranging in size up to the LCU. With a maximum deadweight tonnage of 27,150 long tons at 32-foot draft, one of these ships could deliver enough lighterage in a single load to satisfy a substantial part of the total contingency support requirement. Three SEABEE's are now planned.
The multipurpose ship (MPS) designed by Military Sea Transport Service, and proposed for serial construction in the next few years will also carry lighters up to the size of the LCU in a dry well. If the MPS project is funded, a usable additional emergency lift capability will be available.
The third alternative is construction of lighterage that can deliver itself to the operating area. The beach discharge lighter (BDL) LIEUTENANT COLONEL JOHN U. D. PAGE sailed from continental United Stales to Vietnam in 1966 and has done yeoman service in Southeast Asia for nearly four years. Funds have been requested for construction of additional BDL's of advanced design.
The three concepts are all technically feasible, and it is evident that lighterage can be made compatible with the rapid deployment strategy. The choice among these approaches depends upon which can best satisfy the oversea operational requirement.
The Container-Lighterage Gap
While the rapid deployment concept was being evolved by Defense planners, the shipping industry was developing the containerization concept, which today is the dominant influence in ocean shipping development.
Over half of the military cargo shipped to Europe is now containerized. World-wide, over 20 percent of military general cargo moves in containers. It is estimated that within the next two or three years the proportion will reach 35 percent, and the exploitation of containers has only begun. Preliminary studies indicate that most ammunition, except artillery shell, can be loaded efficiently into standard 20-fool van containers, and shell can be loaded efficiently into half-height 20-footers. Refrigerated cargo is now moving in containers and within the next few years may be containerized almost completely, simply because standard reefer ships are not cost-effective and therefore are being phased out of service without being replaced. Even lumber and other construction supplies can be containerized. Containerization of these commodities should afford the same economic advantages that it does for general cargo and ammunition.
The old, slow, break bulk ships which have long composed the U.S. dry-cargo merchant fleet are being replaced by specialized ships, most of them container ships, at a ratio of up to one for seven. The maritime administrator recently estimated that 500 to 600 break bulk ships will pass out of service in the next four years. To offset this loss of capacity, 146 container ships with a combined capacity of more than 60,000 containers will be in service under the U.S. flag by 1972. The trend in new construction is toward greater size and higher speed with Sea-Land's 22,000 deadweight ton 33 knotters, recently approved for construction, leading the field for the moment.
Within a very few years, container ships will constitute the greater part of the efficient general cargo capacity of the U.S. merchant fleet, with barge-carrying ships, also largely dependent on containerized freight, forming a substantial part of the remainder. Containerized freight capacity will be the principal shipping resource available for support of military logistics from the late 1970's onward.
Most of the new ships will be non-self-sustaining, because shipboard gantries increase construction costs significantly and reduce carrying capacity. The ships will depend upon highly efficient modem terminals for loading and unloading.
The Contingency Container Terminal
ln the United States, container terminals are being built as rapidly as municipalities can find money for them. Foreign ports on primary trade routes are demonstrating similar enthusiasm for investment in new terminal facilities. As a result, the outloading of container ships under emergency conditions does not appear to present a problem.
Discharging container ships in foreign areas under emergency conditions will, however, be another matter. The contingency-preparedness mission requires U.S. military forces to be able to operate in underdeveloped areas where sophisticated terminal facilities are not available.
The number of self-sustaining container ships available for contingency support may not be adequate to satisfy large-scale military requirements. Therefore, the contingency terminal system must be designed to service non-self-sustaining ships, and the problem of getting containers off the ship must be solved before the lighterage problem arises.
Discharge of container ships without fixed container terminal facilities will require unloading at anchorage and lighterage of the cargo to the shore, or use of special gantry ships to offload the container ships.
The contingency container terminal must provide the same ship turnaround rate that fixed terminals provide in peacetime. The container ship fleet will consist of fewer ships than the break bulk fleet of the past, and these ships must be kept working at maximum productivity in order to deliver the required tonnage over a specified span of time. Therefore, jury-rigged systems—for example, unloading with floating cranes to flattop barges or to break bulk piers, which would keep a container ship in port as long as a break bulk ship discharged conventionally—are not operationally tolerable.
A few self-sustaining container ships might be held in the operating area for use as crane ships. However, withdrawal of working ships from ocean carriage would be counterproductive, since every available bottom would be needed to support a substantial combat operation.
The Navy has developed a design for a portable port that resembles a large self-propelled pier ship. The design provides for two container gantries as well as a heavy lift derrick. This concept is entirely workable. The disadvantage of the proposal is its cost, more than $60 million for a basic pier ship with causeway equipment.
Old tankers or ore ships could be modified to carry gantries. This would require rails and deck stiffening to be installed on selected ships in peacetime, gantries to be stockpiled, and cranes to be erected on the ships at the onset of an emergency. The total modification cost would be perhaps $3 million a ship, the ships themselves representing sunk costs. This is a low-cost alternative and appears to be the most reasonable and practical solution so far suggested.
The process of transferring containers from the hold affects the characteristics required in the lighter. The importance of maximizing productivity of container ships makes ship turnaround time a controlling consideration in discharge operations. The limiting factor in container ship turnaround is gantry cycling time. Therefore, the first qualitative requirement of the containerized freight lighterage system is that it permit the gantries on the crane ship to maintain their optimum cycle rate.
Operations at the shoreline also affect lighter design. The time-consuming and manpower-using transfer operation at the shoreline would be eliminated if containers were placed directly on trucks at shipside. Unfortunately, the Army inventory does not now include trucks and trailers suitable for hauling 20-foot containers. The M127 semitrailer is too long and does not have the required load capacity. Military straight-truck chassis do not have the capacity or sufficient frame length to handle containers. Suitable commercial trucks are, of course, readily available. A straight truck and full trailer, each carrying a 20-foot container, would make a practical and efficient rig, which, with a cab-over-engine truck design, could have an overall length no greater than about 50 feet. The container truck/trailer combination would require no more cross-country mobility than that of the commercial design Kenworth truck with Eidal trailers. These trucks were used successfully over the sands of Cam Ranh Bay, after the need became apparent for mobility greater than standard Army trucks provided.
These aspects of shipside and shoreline operations establish several desirable lighter performance characteristics. Optimizing the gantry cycle rate requires that the lighter provide a stable platform on which containers can be spotted without delay and without undue hazard to the lighter crew and calls for minimum time loss in replacing loaded lighters with empties at shipside. The desirability of loading containers directly to wheels indicates the need for an efficient roll-on-roll-off lighter.
Lighterage System Alternatives
The possibility of using heavy lift helicopters (HLH's) and air cushion vehicles (ACV's) in lighterage operations has been discussed for a decade and a half. HLH's, it has been suggested, could telescope the several ocean terminal and port clearance operations into a single movement, from ship to inland storage point, while the ACV could move from shipside all the way to the depot at high speed. In either case, rapid cycle rates would be expected to generate enough productivity to pay for the high initial cost of the equipment.
The SHEDS exercise, conducted by American Export lsbrandtsen and Sikorsky in 1967, demonstrated that skycranes can unload containers, within the load limits of the helicopters, from a ship's deck in weather which makes surface operations impossible. However, an HLH with the capacity to handle a container of 23-tons plus is unlikely to be available for employment by the time container ships become the primary ocean lift capacity under the U.S. flag.
The operational shortcoming of the ACV is its limited ability to climb grades. At Cam Ranh Bay, for example, the ACV could not climb the steep hills that must be crossed to reach the ammunition depot. However, this limitation does not bear on its over-water performance, and the proposed Bell SK-10 will be able to carry two 20-ton containers and a truck and trailer to transport the containers to the shoreline. This 60-ton skimmer will have a drive-through deck for rapid unloading and reloading, and its ship-to-shore cycle time should be short enough to offset its relatively small capacity. Subject to evaluation of its rough-water performance at shipside, the ACV appears to have real potential for use as an emergency container terminal lighter. Even at $1.5 to $2 million, it would not be considered expensive, if it were an element of a high-productivity terminal system.
Conventional landing craft, like the LCU, could be delivered rapidly to the operating area and used to move containerized freight from ship to shore, if SEABEE type ships were available. However, an LCU could move only two double-bottom trucks at a time and the replacement of loaded craft with empties at shipside would waste gantry time. The new Navy LCU has a drive-through deck, but if the standard Army 1466 class LCU were used in a RORO operation, it would be necessary to back empty trucks onto the landing craft at the shoreline, a nearly impossible job with full trailers behind straight trucks. Landing craft are small capacity vehicles without the high cycle rate which makes ACV's attractive, and large numbers of them would be needed to support container ship discharge. Ship turnaround time would still be something less than optimum. The cost of using landing craft for container lighterage would be high in men, equipment, and ship lay time.
Conventional barges could be used to lighter containerized freight and, like landing craft, could be transported by SEABEE. However, barges are still slower and more unwieldy than landing craft and cannot deliver cargo over the beach without prepared landing points. Container ship operators wince at the idea of unloading their ships by dumb barge.
MEXEFLOTE barges overcome two disadvantages of conventional barges: they can be self-propelled and they can beach without prepared sites. MEXEFLOTE pontoons are easier to transport than landing craft or conventional barges, but they have the disadvantage of small load capacity, in container ship terms, and in RORO operations, trucks would have to back onto them.
Large ramp barges, once they had been delivered to the objective area, would provide steady shipside platforms for a large number of trucks and could beach without prepared sites if the bottom were not too shoal. Unfortunately, barges of this size exceed the capacity of the SEABEE and therefore could not be delivered to the objective area quickly enough to meet rapid deployment requirements.
None of the amphibian vehicles are suitable for container lighterage. The LARC-V and LARC-XV are too small and the LARC-LX, while it has a 60-ton weight capacity, has a deck too small for RORO operations and would be inefficient carrying containers without wheels.
The large, self-propelled, beach discharge lighter (BDL) is the only Army lighter that solves the deployment problem by sailing itself to destination. It has good drive-through RO/RO capabilities and can beach without a prepared landing site. It has the power and propulsion system to hold steady at shipside in rough water so that gantries can spot containers on trucks without delay. In addition, it is adaptable to a wide range of secondary tasks including intracoastal distribution.
The proposed MARK II beach discharge lighter has open deck space for enough trucks to carry about sixty 20-foot containers. In a ship-to-shore lighterage operation over fairly short distances, such a large craft might not be usable to full advantage, and a smaller vessel might prove a better buy for general application. On the assumption that the minimum ship-to-shore turn-around time would be an hour to an hour and a half, the minimum economical lighter capacity would be from 20 to 24 containers, that is, from 10 to 12 double-bottom trucks. Clear deck space about 36 feet wide by 150 feet long would be required. With bow and stem ramps, bridge and machinery space, a craft with a 40-foot beam and a 225-foot-overall length would be indicated.
From the overall system viewpoint, the large, self-propelled beach discharge lighter, similar to the MARK II, appears to be the most suitable vehicle for moving containerized freight from ship to shore in a contingency terminal operation. The large air cushion vehicle, when it has been successfully developed, may also be useful in the container lighterage role. The MEXEFLOTE pontoon system is a potentially valuable auxiliary system.
Conclusion
A contingency container terminal system consisting of a two-gantry crane ship, three or four beach discharge lighters, and two to four truck companies equipped with double-bottom chassis trucks designed to carry 20-foot containers could unload and deliver to a depot about 450,000 measurement tons of containerized freight monthly. Total manpower cost for the terminal system would be about a thousand men and officers, approximately a tenth the number needed to handle the same tonnage by current methods. Equipment for the terminal system probably would cost between $15 and $30 million, excluding the initial cost of the crane ship but including its modification cost, procurement of lighters, and procurement of trucks. The cost estimate also provides for acquisition of modern pontoon equipment for work boats and utility piers.
Three or four port packages would be required to support multiple concurrent contingencies and to permit operations at several points within a single large theater. The total cost might run about $20 million a year for a five-year acquisition program.
The greater part of the Army's effective lighterage inventory is being worn out in Southeast Asia. In addition, much of the equipment now on hand is rapidly approaching bloc obsolescence. Therefore, a substantial investment in lighterage will be required during the next few years in any case. Application of that investment to an emergency terminal system able to handle containerized freight effectively and efficiently would cost little more than it would to replace the present fleet with current designs.
The inability of the present Army lighterage fleet to deploy rapidly to an operating area and to handle containerized freight jeopardizes U.S. strategy for limited war. A new fleet, designed to execute the logistics support mission of the late 1970's, is as essential to U.S. strategy as combat-ready divisions. And the early 1970's are already upon us.
Colonel Frank B. Case is Chief of Staff, Military Traffic Management and Terminal Service, Washington, D.C. He was previously assigned as Chief of Staff, HQ, U.S. Army Support Command, Saigon, USARPAC, Vietnam. Prior to that, he was Commanding Officer, 48th Transportation Group, USARPAC, Vietnam. Colonel Case is a 1965 graduate of the U.S. Army War College.
| Date Taken: | 12.12.2024 |
| Date Posted: | 12.12.2024 10:24 |
| Story ID: | 487314 |
| Location: | US |
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