likely to experience, and will not raise doubt in the minds of ships' officers and passengers.

Keel Plates. There are at least three types of keel plates which are considered suitable for attachment to the shank of the lifting hook; they are designed so as to stand a stress slightly in excess of that taken by the hook. 'Out of sight, out of mind,"

can well be applied to keel plates which are usually fitted under the platforms of end lockers, but open to conditions where damp, etc., have a detrimental effect on their lasting qualities.

In the case of open lifeboats of Class I., 25 ft. to 30 ft. in length inclusive, which are not lifted by davits at the extreme ends, a very satisfactory type of keel plate is illustrated at Fig. 169. This consists of a steel plate cut out from an ordinary mild steel ship's plate with the jaws turned up to suit the lower end of the shank

of the lifting hook. This plate is fitted on top of the keelson and security is made by screw bolts with countersunk heads bearing

SPLIT PIN

KEELSON

WOOD CHOCK

HOG

KEEL

FIG. 170.-Type "B" keel plate.

on a plate fitted on the underside of the keel, the nuts being hove up on the keel plate. Care must be taken to see that the ends of the screws are cut and slightly clenched over nuts. This type of keel plate has the advantage of a securing bolt fitted immediately at the centre of the shank of the lifting hook, in a direct line with the pull. The nut can be hove up securely with the aid of a box spanner.

The heel of the shank can be formed into an eye to suit the jaws of the keel plate (as shown in section at Fig. 169), by working

A

KEEL

half-round iron into a bulb, (illustrated in Fig. 167), then flattening the sides to suit the jaws and a hole drilled to take the securing pin.

Satisfactory tests have been carried out on hooks formed in this fashion,

SLIGHTLY COUNTERSUNK with the result that the

FIG. 171.-Type "C" keel plate.

shank of the hook fractured before any impres sion was made on the eve. The jaws of the keel plate prevent the hook from turning, and there is, therefore, no necessity for a square neck in the

latter to be fitted in way of the gangboard.

An alternative method is often adopted in the Clyde district, by fitting two plates, the one forming the jaws being joggled

under the plate attached to the keelson in the ordinary way, having the centre bolt as a means of securing both the curved and flat plates. Very little material is saved by adopting this principle, but a great saving of labour and cost is gained. However, the standard method is considered preferable.

For lifeboats from 21 ft. in length to 24 ft. inclusive, a keel plate, illustrated in Fig. 170, is considered sufficient for the purpose.

The results of tests prove the necessity to limit the use of this bridge pattern type of keel plate to boats not exceeding 24 ft. in length, or where there is a greater dead load on the lifting hook than 3.9 tons.

The shank of the bolt is screwed at the heel and secured by nuts fitted below and above the bridge, with a split pin inserted through the lowest nut and shank of the bolt.

Care must be exercised by the smith to preserve a perfectly fair and level surface on the bridge clamp, for the reception of the securing bolts, and the nuts on the lifting hook. The arrangement is shown in Fig. 170.

For lifeboats not exceeding 20 ft. in length, the shank of the lifting hook is carried through the keelson and keel, being screwed into a plate of the type shown in Fig. 171. The plate is slightly countersunk which allows the end of the shank of the hook to be well clenched over.

Table XX. specifies the various dimensions of this type of plate to suit the different lengths of lifeboats.

TABLE XX.

SCALE OF SIZES FOR KEEL PLATES OF TYPE "C" FOR BOATS 20 FEET IN

Arrangement of Securing Lifting Hook at Gangboard.— All lifting hooks which are fitted with keel plates illustrated in

Fig. 169, viz. Type "A," need not have the square neck in way of the gangboard, but as the latter is somewhat weakened by being cut for the insertion of the eye at the end of the shank, the bolt is held rigidly in position by the aid of a steel plate, in. in thickness, fitted in halves and recessed into the gangboard, being secured by six bolts with nuts hove up on washers fitted on the underside of the gangboard. The screws must be cut and clenched over the nuts. This arrangement is illustrated in Fig. 168.

C"

All lifting hooks having keel plates of Type "B" and (Figs. 170 and 171), are required to be forged with square necks at the gangboard to prevent the hook from turning, and fitted with a plate recessed into the gangboard for half of its thickness, and well secured with four bolts, in the same fashion as previously described for the larger hooks. The type of plate used is shown in Fig. 168.

It is necessary to give every support to the lifting hooks, and relieve the stress on the boat. For this reason the gangboard is made of the same material and thickness as the thwarts, having one end well bolted to the cross thwart and the other end well secured at the apron, and to a cross piece attached to the rising. A slight check is given to the gangboard when crossing the thwart, as illustrated in Fig. 83.

The lifting hook should not project above the line of the gunwale, otherwise it would prove a source of danger from passing ropes. At the same time there must be a sufficient distance between the point of the hook and gangboard for manipulating the link on the block, and a limiting dimension has, therefore, been inserted at "G" in Table XIX., giving scantlings of lifting hooks.

The forward hook must look aft, and the after hook must look forward, that is to say, both lifting hooks look toward amidships.

Considerations when Boat is lifted near the ends. Special precautions must be taken when the lifeboats are lifted at the extreme ends, as in the case of Welin's Quadrant Davits. Reference should be made to Fig. 168. The fastenings of the deadwood, keelson and keel need to be carefully considered in their relation to the securities of the keel plate, and so arranged that the fastenings to the frame combination of the boat may serve the double purpose of also securing the keel plates of the lifting hooks.

The distance between the lifting hook and the stem or sternpost head depends on the type of davit fitted to the vessel.

In all cases, whether the lifeboats are lifted near the ends by a special type of davit or by ordinary radial davits, the position of

the lifting hooks should be obtained from the shipbuilder, before the frame combination is commenced, to enable every consideration to be taken into account in regard to the securities.

When fitting the keel plate, the lugs should be of sufficient length to allow for the insertion of the pin to take the heel of the lifting bolt, as there is not much room to spare between the planks at the extreme ends, particularly forward.

The securing bolts are arranged square to the keel plate so as to avoid tapered washers under the nuts. The heads of the bolts are square, or oblong, to suit the bearding of the stem, which prevents them turning.

If it is desired to secure the bolts through the stem-band, the operation is one which necessitates great care. A batten mould is made round the face of the stem giving the position of the bolt holes, and the information is transferred to the stem-band, which of necessity has to be made of heavy scantling to provide sufficient bearing for the bolt heads.

TABLE XXI.

SCALE OF SIZES FOR KEEL PLATES WHEN OPEN BOATS OF CLASSES I. AND III. ARE LIFTED NEAR THE ENDS.

Distance between centre of lugs and bottom of keel plate to be sufficient to allow for insertion of securing pin.

Before the keel plates are made, the boatbuilder makes an inside mould to the curvature of the deadwood and keelson, and from this he makes another mould which the smith can apply to the keel plate during the operation of forging. The keel plate will fit dead-home to its work, if this precaution is taken.

A good combination in way of the keel plates is shown in Fig. 168. The keelson is run as far fore and aft as the deadwoods