d. Launching Hoists, Elevators, and Ways. The most common types of equipment used 

 in marinas for transferring boats between land and water are listed below: 

 Davits Mobile cranes 



Forklift trucks Overhead-rail launchers 



Jib-boom cranes Stiff -leg derricks 



Lift slips Straddle -truck boat hoist 



Marine railways Vertical-lift platforms 



Four of these types will not be discussed in this study for various reasons, and the reader 

 may consult Chaney (1961) or some other text if detailed information is needed. Mobile 

 cranes, either truck-mounted or crawler-mounted, are too expensive for boat launching 

 alone, and can be justified only where used in conjunction with some ancillary operation 

 that requires this type of equipment. Marine railways are rapidly becoming obsolete because 

 of high cost, waste of space, and lack of versatility. Vertical-Hft platforms are used mainly 

 for large craft (25 tons and over) and are not normally a component of a small-craft harbor. 

 Davits are for smaller craft and lack the versatihty of other launching devices. 



Of the six remaining types of boat-handling equipment, two are completely mobile and 

 most versatile— the straddle-truck boat hoist and the forklift truck. The hoist is similar to 

 the lumberyard truck, but is designed for boat handling service. It is Umited to the boat size 

 the hoist will handle by its load-carrying capacity and straddle clearance, and must be used 

 in conjunction with a launching well or parallel piers (Fig. 126). Some models have one 

 open end so that boats with masts or superstructures can be handled, as shown in Figure 

 126. All are proprietary vehicles, and the costs, dimensions, and capacities can be obtained 

 from the manufacturer or distributor. Construction of the launching well must follow the 

 principle outUnes for construction of bulkhead walls, except that the well walls must extend 

 down to the design depth of the basin and be capable of supporting the extra surcharge 

 loading of the vehicle and the design boatload. The cost of constructing the well or parallel 

 piers frequently exceeds the cost of the vehicle. 



The forkUft truck used for boat launching has a fork ladder with the capability of 

 hyperextending down over a bulkhead wall to the depth required to place the forks under 

 the hull of a floating boat. Because of the eccentric loading, forkUfts are only available in 

 capacities for lifting smaller craft (up to about a 30-foot length). All outboards and some 

 inboard cruisers have most of their weight near the stern and can be Ufted stern -to, with the 

 keel parallel to the forks. This greatly facilitates placing the boats in dry storage racks 

 (Fig. 127). Because of a limited downward reach, forkUfts are best suited for use in marinas 

 with little water level fluctuation. In marinas with large tidal ranges, they may be used for 

 repair and maintenance work on the boats if not inconvenient to await a high tide. However, 

 this would be impractical for daily operational use. Although no boat well is required for a 

 forklift, the bulkhead wall for launchings and retrievals must be designed for the additional 



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