TRIMMING SHORES

Shores must be trimmed to fit the shoring structure. The trimming must be done in such a way as to prevent splitting or chipping of the shores. If shore A in figure 7-15 is to fit against a plane surface of shore B and if it must take a load in compression, the end of shore A must be cut square and perpendicular to its long axis.

A sharp point must never be used when a shore will be required to withstand pressure. A pointed end will slip and curl and allow the shore to work loose and move. Figure 7-16 shows correct and incorrect ways to trim shores to present a flat surface at each pressure area.

Shores are sometimes notched at the end to fit against other shores. However, this method should not be used if you expect any great pressure. A safer method is to cut a socket in the side of one shore and fit the butt of the other shore into the socket. This method is illustrated in figure 7-17.

Figure 7-16.-Trimming shore to deck.

Figure 7-17.-Socket cut in shore.

GENERAL SHORING RULES

Most shoring is done to support bulkheads that are endangered by structural damage or weakness caused by a hit or by the pressure of flooding water. The pressure on the bulkhead of a flooded compartment is tremendous. Expert shoring is required to hold such bulkheads in place. Some of the general rules to remember in connection with shoring bulkheads are as follows:

. Always allow a large margin of safety. Use MORE shores than you think you need, rather than fewer. . Spread the pressure. Make full use of

strength members by anchoring shores against beams, stringers, frames, stiffeners, stanchions, barbettes, and so forth. Place the legs of the shoring against the strongback at an angle of 45

Figure _{7-15.-Trimming shore to shore.}

or 90 if at all possible. Figure 7-18 illustrates the

Figure 7-18.\Shoring against horizontal pressure.

Figure 7-19.-Shoring angles.

simplest and strongest shoring structure; figure 7-19 shows shoring angles. 

. Do not attempt to force a warped, sprung, or bulged bulkhead back into place. Place the _{shoring so that it will hold the bulkhead in its warped or bulging position.}

. _{When possible, strengthen the main shores with auxiliary shores.}

The same general rules apply to shoring a hatch or a door. However, the entire hatch or door should be shored and the pressure should be spread over both the hatch cover or door and the supporting structure, as shown in figure 7-20. Remember that hatches and doors are the weakest part of the bulkhead or deck in which they are installed. Shoring doors and hatches may be complicated by the presence of scuttles and quick-acting handwheels. In this situation, it will be necessary to arrange the shores in such a way as to clear the wheel. A basic rule is to put as many points of pressure on the closure as there are dogs on the closure.

Figure 7-20.-Shoring a hatch.

The success of any shoring job depends largely on the way in which the timbers are wedged. As the shoring job progresses, check carefully to ensure that all of the wedges are exerting about the same amount of pressure on the member being shored. Use as few wedges as possible to obtain satisfactory results. Always drive the wedges in uniformly from both sides so that the shore end will not be forced out of position. Lock the wedges in place so that they will not work loose and cause the shoring to slip. Figure 7-21 shows one method of locking wedges in place.