CONCRETE. PUDDLE.
"Have you managed to squeeze any 'extra' profit on the quiet out of
concrete?"
"Yes, twenty or thirty years ago, but there is not much to be got now.
Since a few engineers took to writing upon the subject they have
reminded or informed others pretty well what to look after, but there
were not many thirty years back that knew how it ought to be made; and
you see, although one receives the materials, the concrete has to be
made with them, manufactured, as it were, on the work, and you can
spoil the best Portland cement that is, was, or ever will be made in
the proportioning, mixing, and blending it with bad sand and gravel, or
dirty broken rock.
"They handed me the Portland cement, and all the specification said
was, 'All concrete shall consist of 1 of Portland cement to 6 of clean
gravel, and shall be mixed and deposited in a workmanlike manner [which
we consider means as the workmen like] to the entire satisfaction of
the Company's engineer.'
"This was drawn up by a civil and mechanical engineer, which is a
big-drum kind of title, and I should think covered corkscrews and
manufacturing machinery, and everything else under the sun that can be
handled at any time, including a 6-inch drain, the Forth Bridge, and
the Channel Tunnel thrown in. It's too much, it seems to me, for one
man to completely understand; and I once heard a celebrated engineer
say that, with a few brilliant exceptions, such a man knew thoroughly
neither civil nor mechanical engineering--life was too short. I don't
presume to say anything, but his specifications of our kind of work
might have been more exact; still they were sources of joy and comfort
to us.
"Machine mixing was hardly known at the time I am particularly
referring to, and the Portland cement was of all qualities, good, bad,
and indifferent, and some as I really can't say had any quality in it
at all, and was utterly unlike what you get now. It was then sometimes
bought on the same principle as going to the first shop handy, and
saying, 'Small bag of cement. How much?' There was no name on the bag,
for no one wished to own he had made the cement, and it was indeed of
illegitimate origin, and had no parents.
"The cement came, and we did pretty well as we liked, for the inspector
knew nothing about it; in fact, we were all in the same boat. But what
a lucky thing it is that there is such a thing as a margin of safety!"
"You mean the difference between the strain a thing has to bear in
ordinary use and what will break it?"
"Yes, that is it. One day an engineer said to me, 'There is a large
factor of safety in this case, which is fortunate.' I thought he was
talking about a flour factor near the works that also sold fire-escapes
and fire-extinguishers, so I said, 'He weighs nearly eighteen stone,
and I should call him big rather than large, for he is like the prices
at which he sells flour, and charges a penny a quartern too much; but
he is greatly respected in the neighbourhood by those who don't know
what fair prices are, for he is so oily and civil, as just suits a
lot.' Between you and me, he swindled them, and beat us for 'extra'
profit.
"The engineer looked as if he could not at first make out what I was
talking about, and, as it turned out, I did not know what _he_ was. He
seemed to enjoy himself, and let me finish my sermon. He then explained
to me what we call 'margins' of safety, and what they call 'factors' of
safety are the same goods."
"You have learnt something now."
"I have, another name; no doubt their word is the right one, but they
ought to consider the likes of us are not poets, or fed on stewed
grammar, and should remember we were boss-gangers once, and have
blossomed into sub-contractors.
"Let that pass. You should have seen the cement. It was lucky we never
had to sift it as we do now, or we should never have got any through a
forty-to-the-inch mesh. It was just like fine sand, and nearly the
colour of it, too, instead of grey. I have had a fair experience with
Portland cement now, for we had testing-rooms, machines and troughs,
fresh and sea water, slabs, and a host of other detective apparatus at
the last dock works I was on. However, the cement we had and I was just
referring to, was pretty nearly all residue, and of course it did not
stick the gravel together except in streaks that had good luck rather
than anything else. And the gravel! Well, it is an elastic truth to
call it gravel, for it was dirty; and I conscientiously feel I am close
to thinking I am not speaking in accordance with the principles of
strict veracity if I call it gravel.
"And the mixing! Well, there was not much of it, just a turning over or
two, and we deluged the stuff with water so as to make it easy to
handle, and we hurled it into the foundations as we pleased and at all
sorts of heights, just as might happen to be convenient. I did not
trouble myself about it then, but I do now, for I had a month or two in
and about the testing places when there was no other job for me that
suited, and I firmly believe almost all the failures of Portland cement
concrete occur because the men that used it do not understand it, or
the specification is not carried out, or is wrong somewhere. The best
goods in the world want proper treatment, and, after all, the abuse of
a thing is no argument against its use. Some quarry owners and stone
merchants don't like cement concrete; it is poison to them, because it
hurts their trade. It is my opinion, founded on what I have seen and
know, that Portland cement concrete is grand stuff when properly made;
but you can't make the 'extra' profit on it you could, unless you can
forget to rightly proportion the material. I mean leave out anything on
the quiet you find is more profitable when it is absent; and now mixing
machines are always used on works of importance where concrete is made
in any considerable quantity, that is the only way you get a chance of
a bit 'extra,' at least so runs my experience.
"Bless me! when I come to think of it, it is really wonderful that some
of the concrete I have cast in has set at all, and don't believe it can
all have set; for, first, the cement was wrong, then the gravel was not
gravel, the sand was like road siftings, no trouble was taken to
proportion the materials properly, and no mixing was done rightly, only
an apology for it. The water was dirty, and used anyhow, and if a lump
got a bit stiff it was rolled over, broken up in the trench and watered
down below. Some went in like the soup that has balls in it, and we
threw the concrete (?) down just anyhow. The inspector, as I said
before, knew nothing much about it, although he was a beautiful kidder
and could patter sweet and pretty just as if he were courting, and the
engineer was away, so the road was clear for a bit 'extra,' and we took
it."
"Now, how the dickens could any concrete be right with such treatment?
It is cruelty to expect it."
"I left those works, and the engineer got corpsed, so he is past
blaming; but, fortunately, the middle wall of the dock that got
strained the most--the one in which was some of the concrete (?) I have
been telling you about--had to be removed for improvements, and when
they pulled it down I heard the concrete was in layers like thick
streaky bacon, a layer of gravel with hardly a bit of cement in it,
then a few lumps of solid on the top and hard as all would have been if
the cement, gravel, sand, proportioning, mixing, and the putting into
place had been done properly; then another layer of open stuff that had
stuck together a bit, and then a lot of soft oozy rubbish, like decayed
cheese, bad, coarse cement, you know, that would not or could not hold
together and had done the 'fly' trick, you know, had cracked about, the
coarsest part of the cement The streaks were there because we watered
the cement so much that it was not concrete but weak grout, and bad
too; and it could not drain down because one of the thin, hardish
streaks, already set, stopped it, and it was bound to make friends with
the gravel and dirt somehow, although trying to shun such company by
running away and so get off duty. It was the same all the way through,
and there were a lot of holes in it caused by the nearly set lumps
coming together and slightly sticking, and therefore preventing the
other material from filling the voids. _Hardly a cubic yard of the
whole mass was the same._
"That is what I call a real bit of scamping; but, honestly, I did not
think I was putting it in so bad as that, but I then knew hardly
anything about the material. I shall never do it again, for I know I
shall not get the chance, besides we all must draw the line somewhere;
but there, a lot is now known about concrete that was only in the
brains of a very few then.
"As the cement is now supplied to you, I often put it in a bit thick,
that is when I have to find the gravel and sand. It would be the other
way about under different circumstances; but at the present time, with
Carey's concrete mixer--which, luckily for plunder for us, is the only
machine that measures and mixes the materials mechanically, and turns
out from 10 to 70 cubic yards of concrete per hour--you do not get much
chance of 'extras' and none with it; and concrete mixing is now nearly
done as carefully as mixing medicine, and I don't regard concrete as
fondly as I used to, for no 'extras' worth thinking of are to be made
out of it. My old love, consequently, is cooling off, becoming warm and
perhaps distant respect, not much else; but good Portland cement
concrete is the best material, bar granite, I know of, if properly
used, as it is then all the same strength--that is when the Portland
cement is right, the proportions, mixing, and depositing even and
proper, and the gravel and sand really clean sharp gravel and sand. You
see, in that case, it is uniform throughout, and, after all, what is
the good of the hardest stone or brick when you have a weak mortar to
join them together which cannot nearly stand the same strain in any
direction as the stone or brick?"
"You are right, it is simply waste. Like deluging good spirits with
pure water, and spoiling them both. Lucky you had finally left those
dock works before they pulled the middle wall down, or you might have
had a bad quarter of an hour in a very sultry atmosphere."
"After that we will have a toothful neat."
"That's warming and is real comfort."
"I have never had much to do with concrete, but I remember seeing a lot
go in on some dock works where I had some puddle to make for the
cofferdam, and I got something 'extra' out of that."
"How did you do it?"
"Well, you know, working such stuff all day and nothing else makes
anyone rather sick of it, it is like breaking stones for metalling, I
should think, and the weariness of it makes the big stones have a
tendency to hide and cause the face to look small and even. I had a
dozen men besides casuals, and all old hands at the game of 'extras.'
We had to, or were supposed to, work up a certain right proportion of
sand with the clay so as to prevent the puddle cracking and keep it
sufficiently moist. I own we sometimes let the clay have a taste of
peace; in fact, between you and me, we were going express speed, and
'extras' was the name of our engine.
"One day the resident engineer came, and somehow got up close to us
rather unawares, and took us by surprise. Of course, the material ought
to have been worked the same throughout, and we nearly did it, but
nearly is not quite. He seemed to sniff out that all was not just as
right as it might be, and said:--
"'Don't forget to work it up thoroughly. You have a good price, and it
is important the clay should be uniformly mixed with a little sand.'
"'Certainly, sir.'
"I generally agree with my boss, it pays best. So I at once called out
sharp to my chaps, as if all I loved in this world was at stake, 'Don't
fear mixing it, lads. Get it well mixed.'
"One of them, he was a new chap to me, and belonged to the militia I
found out, turned round, and said:--
"'All right, boss; I always make the broad-arrow kitchens in the camp,
and the flues and the openings for the Flanders kettles, so I know how
it ought to be done; but if you think I'm a white-faced doughey [i.e. a
baker's man] I am not, and you had better fetch a batch of dougheys and
start them at work feet and hands. It will make them sweat. That
puddle, I tell you, is as well mixed as the dougheys do the different
kinds of flour, and call all the bake the best and purest bread, and
make it smell sweet with hay water.'"
"I suppose you silenced him quickly?"
"No, I pretended to take no notice, for I knew I had spoken too sharp,
but the resident engineer smiled downwards and passed on.
"We had a heap of clay on one side and the same of sand on the other,
and the inspector saw we had from time to time a small mound of clay
and one of sand put separate and measured ready for mixing. We had a
few piles of clay and sand at first measured exactly, and then we got
used to it, and did it by sight only. We were close to the river, or
rather estuary, and used to fill a barrow now and again with the sand
and shoot it over the entrance jetty. A little was taken from each
heap. The engineer knew his book, and would not have it worked from one
or two big heaps, and the sand brought to it, but he would have
separate mounds of about 20 cubic yards at a time. There were nearly
5000 cubic yards of puddle to work up, and as the clay came from the
trenches so we worked it up. A kind of filling and discharging, and
everything on the move.
"I made a nice thing 'extra' that way, but nearly got bowled out, for
one day there was an extraordinary low tide, a low tide was expected,
but a land wind was blowing great guns, and it was the lowest tide
known for fifty years or so. Now, when you start the game of 'extra'
profit you will agree with me, it is necessary to have someone you can
rely upon, or else things may not go exactly as you expect. They may
work wrong, and then you have to look out for squalls when they lay you
bare and find out all. Here, I had been getting a rise out of my
bosses, and blessed if old Ginger's snip, his boy, whom I paid a bit
extra to do the harrowing well out, did not get a rise out of me. It
caused a near shave, too.
"Well, the tide ran down till it laid dry a little sandbank, that is,
some of the stuff that should have been at home in the puddle, had
travelled by the wrong road by the entrance jetty. I did give Ginger's
snip a talking-to, I tell you, after; but it was a near shave, as you
will soon know. I saw the bank, so I sent him down the jetty with two
chaps that knew what was up and got duly rewarded by me. They knew me.
I never forget friends--too good, I am. Not even to borrow from them,
if occasion requires, so that they should remember me in their dreams.
I said to them: 'Stir up the sand, lads, for I think I saw a leg in it,
and a bit of a dress; it may be there has been another midnight horror.
It's really shocking!' And that was true, for I thought the sand was
shocking, and that murder will out, as the saying goes. It was a shave,
for just as the tide began to turn, up came the resident engineer, and
there could not have been more than an inch or two over the sand, but
it soon rises, as you know, and almost walks up. I had not time to call
the men, and there they were, stirring away. It was lucky I thought of
the leg and the woman's dress. So I shouted, 'Come up, lads, it's
nothing.'
"Then the resident engineer started asking me questions; and I was
afraid he might ask the men something, so I kept him as long as I
could, and spun a yarn, and pointed out the spot where a body was found
some time ago, and talked away like a paid spouter, for every minute
that passed was good business, for the water was rising quickly, and I
knew the tide would soon just about put it right. After a little while
the resident engineer went away, and I was rubbing my waistcoat
thinking I had been in another near squeak, but won on the post by a
short head owing to jockeyship, when I saw him down below with a large
black retriever, and the blessed dog was half out of the water. I kept
as far away as I could, but I saw he had taken off his boots and turned
up his trousers, and was walking about on the heap probing with his
stick. He did not stop long, as he knew the tide was rising, and then
he came to me afterwards and said that a sandbank had been deposited at
least 30 feet in length.
"'Very likely, sir; but did you find the leg, or body, or dress of a
woman?' 'No. But I found a lot of sand that would have been better in
the puddle.' And he looked straight at me.
"Well, I had to put on my best sweet, innocent child face, and I
hazarded the mild remark, 'It's the eddies that have done it. I have
known them bring stuff for miles, sir.' It was no use saying from the
other side or nearer, because there was no sand like we had to mix with
the clay for the puddle for many miles, nor could I declare that a
barge had got upset. He did not say anything more, but called his dog
and went to the office. Let me impress upon you that the last 1500 or
so yards of puddle had more sand in them than the first 3500. Tides I
like, and they are healthy and useful; but it is the deuce to pay if
you think you can go against them, as King Canute showed his courtiers,
when he did the chair trick upon the sea-shore. Do you know I go so far
as to think that if a floating caisson were taken about and sunk so as
to lay bare the bed of the Thames in certain places, things would be
found by a little digging that neither you nor me dream of, and perhaps
might not like to see, for even sandbanks at certain times and places
are not pleasant to gaze upon. Eh?"