A lorry drives on empty, gets loaded, and drives off heavier. That is the entire job. For six years one wagon came in and went out at exactly the same weight, and the load was gone.
I ran the weighbridge on nights at an aggregates quarry for eleven years. Six on, six off, ten hours a night, in a portacabin with a window and a screen and a kettle.
The job is arithmetic and it is the same arithmetic every time.
A wagon comes in. It stops on the plate. The screen gives me a number, and that is the tare, the weight of the lorry with nothing in it. I let it through, it goes up to the hoppers, it gets loaded, it comes back and stops on the plate again. Second number, the gross. Gross minus tare is what it is carrying, and that number goes on the ticket, and the ticket is what the customer pays against and what the driver's tacho gets checked against and what the tax on aggregate is worked out from.
It is not a guess. It is a legal measure. The bridge is calibrated twice a year by a firm who come with test weights on their own lorry and stack them on the plate in a sequence, and there is a certificate on the wall of the cabin, and I have read every one of those certificates because there is a lot of night in a night shift.
The whole of my job is one subtraction. That is why I noticed.
The wagon was a green eight-wheeler tipper with no livery on it, which is not unusual; plenty of owner-drivers run bare.
It came in about twice a week, always between about ten past two and half two in the morning, always for the same product, which was 20 millimetre limestone, and always for the same ticket account, which was a builder's merchant forty minutes up the road who were a real firm with a real yard and who I could tell you the name of but will not.
First weight in: eighteen thousand two hundred and forty kilograms.
Loaded up at the hopper.
Second weight: eighteen thousand two hundred and forty kilograms.
Net: zero.
I want to walk through what I did, because everybody who hears this says the same four things and I did all four of them within the first month.
I thought the plate had stuck. So I had him off and back on, twice. Same number both times. Then I had the next wagon in the queue drive on, and it read its own weight correctly, and then the green one drove on again and read eighteen two forty again.
I thought he had not been loaded. So the second time, I walked up to the hoppers, which I am not supposed to leave the cabin to do, and I stood there and I watched the shovel driver put four buckets of 20 mil into that body, and I watched it settle, and I walked back down and he drove onto the plate and it said eighteen thousand two hundred and forty.
I thought he was tipping it somewhere on the site. There is nowhere. It is four hundred metres of one-way haul road between the hoppers and the bridge with a bund on one side and a lagoon on the other and a camera at each end, and I have watched the footage of that run more times than I can tell you and the wagon does not stop and nothing comes off it.
I thought somebody was fiddling the ticket. So I stopped using the automatic and I keyed both weights by hand from what my own eyes read off the screen, and I wrote them in pencil in my own notebook as well, and the numbers were the numbers.
So then I looked in the body.
I did that in the March of the second year and it is the only thing in eleven years I have not written down anywhere official.
He pulled up on the plate for his gross and I went out with the torch and I climbed the ladder on the back of the cab, which you should not do, and I shone the light into the body.
It was full. Four buckets of 20 millimetre limestone, dusty, sat the way it sits, the top of it about a foot below the rave. It was there. I could have got down and put my hand in it.
I climbed down and the screen said eighteen thousand two hundred and forty.
The driver was a man of about fifty in a fleece with the zip broken.
He was not frightening. That is the thing I would most like to get across, because I know what a story like this is supposed to have in it. He was ordinary and slightly bored and he wanted to get on. He said all right mate about four hundred times over six years and I do not think we ever had a conversation longer than nine words.
Once, and only once, I said to him, do you know your wagon weighs the same in and out.
He said, does it.
I said, every time.
And he thought about it, and he did the thing that people do when they are being told something they already know and are deciding whether to bother, and he said, well. It gets there.
And he pulled off.
It gets there. I have had six years to take that sentence apart and here is where I got to.
The merchant's yard signed for it. I have the delivery copies because they come back to us, and every one of them is signed and every one of them says the tonnage on the ticket, and the ticket says what the bridge said, and the bridge said nothing was on there.
So somewhere between my plate and a yard forty minutes away, twenty-odd tonnes of stone that weighed nothing became twenty-odd tonnes of stone that a man was willing to sign for. It gets there.
I rang the merchant once, in the day, on my own phone, and asked for the yard and said I was checking a delivery and gave a date. The lad who answered went and looked and came back and said yes, that came in, all fine, it is in the bays.
I asked him if he could see it now.
He said, course I can, I'm stood in front of it.
It stopped in the November before last. He came in on the Tuesday and he did not come in again, and the account went quiet, and about five weeks later the day shift told me the merchant had gone into administration, which happens to builders' merchants all the time and means nothing.
I have kept the pencil notebook. Two hundred and nine crossings over six years. Two hundred and nine times eighteen thousand two hundred and forty, in and out, in my handwriting, and the calibration certificates for all six of those years on the wall behind me saying the bridge was accurate to within twenty kilos the whole time.
There is one more figure and then I will leave it.
Last winter they resurfaced the haul road, which meant they took up the top and weighed what came off it, because you weigh everything at a quarry, that is the entire business.
Four hundred metres of road, and it came out heavier than the estimate. Not by a bit. By something over four thousand tonnes.
They put it down to an error in the original build records, which is a perfectly good explanation and is probably what it is.
But I did the arithmetic that night in the cabin, on the back of a ticket, because it is one subtraction and one subtraction is what I do.
Two hundred and nine loads. Call it twenty tonnes a load.
Four thousand one hundred and eighty tonnes.
It never left the site. It has been under that road the whole time, and it weighed nothing on the way up and nothing on the way back, and a lad in a yard forty minutes away is stood in front of it right now telling me he can see it.