Part 39 (1/2)

It is desirable that all engaged in directing any part of the work should understand the general course of proceeding which it is intended to pursue, so far as may be found practicable; circ.u.mstances may modify these pre-arranged plans, and may compel a total departure from them, but every endeavour will be made to adhere to them.

GENERAL COURSE OF PROCEEDING.

[Sidenote: To start about noon of Tuesday.]

I propose to commence operations about two hours before high water, or about noon, and to endeavour to get the s.h.i.+p down as quickly as I can into the water, and down to within about 36 feet of the bottom of the ways.

My object in starting at this particular time of tide would be to get the s.h.i.+p into the water, and waterborne to some extent as soon as I could.

[Sidenote: Stop short of end of ways.]

I propose to stop short of the end, in order to avoid the necessity of having to knock away all the sh.o.r.es, and clear the cradle at the evening tide, when it would be dark, and to float on the morning tide, when it would be also dark.

I should propose then to stop about 36 feet short of the end.[162]

[Sidenote: _Evening._ Clear away sh.o.r.es of the 20-feet cradles.]

At low water, although dark, I shall endeavour to knock away the sh.o.r.es of the 20-feet cradles, or as many of them as possible, and clear all from these cradles except the unbolting of the filling-pieces.

[Sidenote: Under favourable circ.u.mstances clear away also _all_ the sh.o.r.es on the port side.]

If the operations have proceeded easily, and the ways not sunk much, I shall also knock away all the long sh.o.r.es on the insh.o.r.e or port side of the s.h.i.+p, so as to leave less to do on the following day.

[Sidenote: Prepare for a further pull at the night's high water.]

I shall then prepare at leisure to place the barges to get one pull of 36 feet, or as much more as I can (as I shall not hesitate to pull the cradles 20 feet off the ways) after high water of that night.

[Sidenote: Last move at 4 A.M.]

Soon after the high water of that night, and when the water has fallen sufficiently to prevent any risk of floating, but while the s.h.i.+p is still waterborne, probably about 4 or half-past 4 A.M., I shall make the last pull; and although it will be in the dark, yet having only one pull to make, and plenty of time to prepare, and no expedition required in the operation, I think it may be easily done.

[Sidenote: Float on high water, Wednesday afternoon.]

The s.h.i.+p will then be left till low water, when we shall clear away everything we can from the cradles, and get all ready for floating at high water on the afternoon of Wednesday.

Provided the mechanical arrangements should prove efficient, the success of the operation will depend entirely upon the perfect regularity and absence of all haste or confusion in each stage of the proceeding and in every department, and to attain this nothing is more essential than _perfect silence_. I would earnestly request, therefore, that the most positive orders be given to the men not to speak a word, and that every endeavour should be made to prevent a sound being heard, except the simple orders quietly and deliberately given by those few who will direct.

In a memorandum of 'Particular Instructions,' dated the next day, October 31, there is the following pa.s.sage:--

_Starting_.--A strain being brought upon all the purchases, and the holding-back purchase being slack, if the s.h.i.+p does not move, the two presses will then be worked; if she does not then move, or if, when moved, she stops and each time requires the presses, the attempt will be postponed, and more moving power applied for the next time.

If, after being started by the presses, the river purchases are found sufficient to move her, the operations will proceed.

In another part of these 'Instructions' Mr. Brunel again shows that he was not, as has sometimes been supposed, under the impression that the friction would be so small that the only important thing to be thought of was to check the s.h.i.+p from rus.h.i.+ng too fast.

On the contrary, he foresaw the possibility of her not moving at all, even with the presses, that is to say, with a force of 1,100 tons over and above the action of gravity. If after moving she stopped, and then required the presses again to move her, this would show that the operation could not be properly carried out, and that the work must be suspended till more motive power was applied. If, again, the river tackle were sufficient to move her, then the work was to proceed, but the friction might even then be so great as to render it desirable to remove all r.e.t.a.r.ding force. He says, in another pa.s.sage in his 'Instructions:'--

It is very likely that no checking whatever at the drums will be found necessary, but that, on the contrary, it will be found desirable to get rid of any resistance by overhauling the heavy chains through the sheaves.