The salient feature of the Reports of the Board's officers on the subject is the consensus of opinion that the form of a boat is the chief factor to be considered in determining its value as a life-saving appliance.
It has been found that while there are many boats of good form supplied to ships, there is yet a large proportion where the boats are not only not so good, but which can only be regarded as unsafe if they had on board anything approaching the number of persons for which they measure.
It is the latter type we are chiefly concerned with; how is it that the form has so deteriorated as to create this concern in our minds? I think the cause is not far to seek; it appears to be the outcome of (1) The shipowner's desire to carry the maximum number of persons in the minimum number of boats; (2) in the efforts of the shipbuilder, as a rule, to carry out the specification in which he has contracted supply the owners with boats at a price, often very low, and naturally he does not sublet his contract with the boatbuilder at a loss; (3) the aim of the competing boatbuilder, which is to build his boats at as little cost price as possible, and yet to provide accommodation for the prescribed number of persons. He is probably limited as to length, and therefore relies on the breadth and depth, in this direction, he is unintentionally assisted by the Board's rule for measurement, viz., (L x B X D x6)/10 or 8; so long, therefore, as he can obtain his breadth at one point for measurement purposes, it is quite immaterial to him how soon he fines away to the ends, with a result that the stability of the boat becomes almost entirely dependent upon the form of a very limited midship section, or the still smaller proportion of same that would be under water when in the loaded condition.
The boat builder may be further restricted as to breadth, and, therefore, he again detracts from the form a boat should have by dispensing with shear and increasing the depth from (*See rule of 14.6.11.) keel to gunwale amidships. This method of building boats enables him to obtain the capacity required by the owner at the expense of the boat's stability and utility.
No doubt when the Life-Saving Appliances Rules came into being, the divisors 10 and 8 for the different sections were deemed safe on the supposition that the usual full form of boat would not be largely departed from; experience has shown, however, that form is frequently sacrificed for the unworthy objects referred to above, and it follows, therefore, that either the form should be improved or a heavier divisor laid down.
It would, I think, be more effective to deal with form, and devise a rule by which we can insure that a boat will be reasonably safe with its load, not merely in smooth water - as in our recent test - but in a sea-way. It is essential, therefore, to draw the attention of the Advisory Committee to the value the Board attach to form, and particularly to that part of it underwater, emphasising the great necessity there is for an increase to the bearing surface of the underwater portion of boats, and this end can, no doubt, be best attained by the putting into practice of the suggestions made by the Principal Ship Surveyor for amending the rules, and which aim at prolonging the form or fullness of dimension of the midship body underwater well towards the ends of the boat. It is well known that by extending the body in this way greater buoyancy and stability are secured without materially affecting the speed. It is often supposed that defective stability due to bad form can be rectified by the disposition of the persons or things, but anyone with real experience of boats in a sea-way cannot fail to realise that this is the wrong principle to work on; granted, therefore, that the question of form must take priority - how can it be best attained? And if we refer to Mr. Archer's method of measurement, as stated in his amendment to the Rules, it will be seen how simple and effective it is. For the purpose of illustration we might take the model of a ship's boat obtained through the Board's surveyors at Glasgow, the dimensions of which enlarged to scale represent a boat of (L) 30.0 X (B) 8.5 X (D) 3.5 and is an embodiment of the proportions amidships and at quarter distance from each end, proposed by Mr. Archer.
It cannot be too strongly urged that for a ship's lifeboat to be fit to carry the number of persons it measures for in any degree of safety, whenever it may be required at sea, the underwater or bearing surface should be carried out to the ends as much as possible and all straight lines avoided. The bows of many of the existing types of boat are examples of the worst possible form for safety, and the counters are as bad - if they can be said to have any.
Depth. - It appears from the reports that the most generally approved ratio of depth to the breadth is 4/10. This has been established, not only by our long experience, but by the numerous tests recently conducted by the Board's surveyors at various ports, and the attention of the Advisory Committee might be drawn to this fact.
It is, of course, necessary also to have a good freeboard, but a well-proportioned boat does not require so much freeboard as the commoner type, as with proper sheer and underwater surface she is easy in a sea-way. If the gunwale is too high there is loss of power over the oars, which is serious when for the safety of the boat she is required to be kept head-on to sea, and with a fresh breeze, even in a good boat, this is not always an easy matter.
It is a matter for consideration that at the tests made by our surveyors the conditions were most favorable, being usually in smooth water of a sheltered dock, and, in not a few instances, considerable anxiety was felt for the safety of those on board when crowded in accordance to the existing rules. If it was thus in smooth water one dare hardly contemplate the results in a sea-way. If the shipowner does not see to it that a safe type of boat is provided, then the number of persons to be accommodated in boats which do not come up to proportions deemed safe by the Board of Trade should be very considerably curtailed.
A. H. Y.,
23.3.12.
