Sacks are weighed sealed on the bridge and the count of items inside is on the label, and the two are reconciled because the weight is what the contract pays on. Sacks off round 14 weigh about twenty two grams more than their contents, which is a letter, every sack, every night, and when the sack is opened and the letters weighed one by one the extra is not among them.
I am the yard supervisor, and the weighbridge is the first thing I check and the last.
How sacks are weighed.
A round's mail comes back in sealed sacks with a label giving the item count. Each sack goes on the bridge, sealed, and the weight goes on the label. The contract pays on weight, so the bridge is calibrated with test weights every morning and the weights are logged.
The average letter is about twenty grams, and a sack's weight divided by its count comes out near that, every sack, every round.
Round 14's sacks weigh one letter more than their contents.
Twenty two grams over, give or take a gram, on every sack off that round, every night, for as long as the bridge has logged, which is nine years.
I found it because I do the arithmetic, and round 14's sacks were always the heaviest per item, by a margin that did not vary with the count, which is what a fixed extra does.
What has been checked.
The bridge, calibrated, and a second bridge, the one at the depot down the road, which read the same twenty two grams over on a sack I took there in my car.
The sacks. Same sacks as every other round, from the same stock, and I have weighed the empty sacks from round 14 and they weigh what sacks weigh.
The contents. This is the test that turned it from an accounting note into what it is. A sack opened on the bench, every item weighed on the letter scale one at a time, and the items added up.
The items add up to the label count. The item weights add up to the sack weight less twenty two grams.
Sealed, the sack weighs one letter more than what is in it. Opened, the extra is not on the bench.
The round.
Round 14 is a town walk that takes in the old streets by the river, and it is the walk that has had the same postman for thirty years, and he is a careful man, and I asked him, without leading, whether anything about his round was odd.
He said the sack was always heavy at the end, and that it had been since his first year, and that his predecessor had told him it would be, and had told him not to look for it, and that he never had.
What that costs.
Twenty two grams a sack, four sacks a night, is a few kilos a month, and the contract pays on it, and we are paid for a letter a sack that we do not carry, which is a small fraud that nobody has committed, and which I have declared, in writing, to the contract manager, who wrote back that the tolerance covered it.
What I do.
I run the yard.
The one thing I have changed is that I seal round 14's sacks myself, at the frame, at the end of the walk, rather than letting the postman seal them.
The reason is a night when I weighed a round 14 sack on the bridge, twenty two over, and opened it on the bench, and weighed the items, and they added up short, as they do, and I put them back in the sack myself, counting, and sealed it, and put it back on the bridge.
Twenty two over. And as I stood there with my hand flat on the top of the sack, something inside it, on the far side from the items, which I had packed to one side, shifted its weight, once, the way a single letter settles when a sack is moved, and there was nothing on that side of the sack, and I have not put my hand on one since.