Buying a second-hand weighbridge: what to check

A second-hand weighbridge typically costs £12,000–£25,000 against £25,000–£45,000 for new — roughly half price for a lump of steel that, if the deck's sound, may honestly have another twenty years in it. The saving is real. So are the ways it goes wrong, and most of them aren't visible in the sale photos.

Why the price spread is so wide

At the £12,000 end you're usually buying a bridge as it stands: older deck, original load cells of unknown condition, an indicator from a discontinued range, sold as seen, loading and haulage your problem. At the £25,000 end a dealer has refurbished it — shot-blasted and painted deck, new or tested cells, a current indicator, a warranty, often installation included. The gap between those two is not padding; it's the cost of everything the cheap bridge might need next year.

The trap is treating the sticker as the cost. Price the whole journey — bridge, move, groundworks, cells, calibration — and compare that against new, using the figures in how much a farm weighbridge costs.

What actually fails on old bridges

• Load cells and cabling. The perennial one. Cells age, water finds its way in, and rodents treat cabling as a project. Cells are replaceable, but a full set with fitting runs to thousands — a sum that turns a bargain into an average deal.
• Junction boxes. The wet failure. Corroded terminals give wandering, weather-dependent readings that are miserable to diagnose. Open the lids and look; tired boxes are cheap to replace, but they hint at how the bridge was kept.
• Deck corrosion — at the ends. Steel decks rot where water and muck sit: the ends, around the cell pockets, and along the drainage paths. Surface rust on top is cosmetic. Get underneath with a torch and a screwdriver and prod the end sections; flaking, scale and thin webs are structural, and deck repair is fabrication work, not paint.
• Indicator obsolescence. A bridge from 2005 may weigh perfectly and still be a liability if the indicator range is dead: no spares, no support, no way to connect it to anything modern. Replacing an indicator is routine, but it's another line on the bill.

Questions for the seller

Straight answers to these tell you most of what the photos won't:

1. Why is it for sale? (Yard reorganisation is a fine answer. Vagueness is an answer too.)
2. Is there a service history — and when was it last calibrated, by whom?
3. Have the load cells been tested recently, and can you see the results?
4. What make and model is the indicator, and is it still supported?
5. Have any cells been replaced — and were the rest done at the same time?
6. Was it verified for trade use? Not because you necessarily need that, but a bridge maintained to trade standard was maintained.

A seller with paperwork is telling you how the bridge was owned. A seller without any is telling you the same thing.

Moving it can cost as much as buying it

A 15–18 metre deck needs a crane at each end and a low loader in between, and your site needs foundations and level concrete approaches exactly as a new bridge would — the groundworks in the installation guide don't get cheaper because the bridge did. A worked example: a £14,000 bridge, £3,000 of cranage and haulage, £8,000–£12,000 of civils, and a set of replacement cells at a few thousand more, and you're within sight of a new surface-mounted bridge with a warranty. Sometimes the second-hand deal still wins comfortably. Run the sum before bidding, not after.

On your site: inspect, then calibrate, then trust

However good the bridge looked at the seller's, it's since been unbolted, craned twice, and lorried down the A-road. Have it commissioned and calibrated with test weights on your own foundations before the first real load — corner tests especially, since cell damage in transit shows up as position errors. The checks and the annual routine that follow are in weighbridge accuracy and calibration. Budget the engineer's visit into the purchase, and keep the certificate as the baseline for every year after.

When paying for new is the better deal

Second-hand suits a farm that wants good weighing for its own records and has the patience to inspect properly. New earns its premium when the bridge will be central to the business — every sale checked against it, software hanging off it, twenty years of service expected — or when nobody has time for the second-hand homework in the run-up to harvest. A warranty, fresh cells and a supported indicator are worth real money; the question is whether they're worth the £15,000-odd difference on your farm, at your tonnage.

Frequently Asked Questions

How much does a second-hand weighbridge cost?

Typically £12,000–£25,000. The bottom of the band is sold-as-seen with unknown cells and an ageing indicator; the top is dealer-refurbished with tested or new cells, a current indicator and a warranty. Moving, groundworks and recommissioning come on top at either end.

What should I check before buying a used weighbridge?

Load cells and their test results, junction boxes for corrosion, the underside of the deck ends for structural rust, and whether the indicator is still supported. Ask for the service and calibration history — its absence is information.

How much does it cost to relocate a weighbridge?

Cranage at both ends plus haulage commonly runs into thousands, and your site still needs full foundations and level approaches — often £8,000–£12,000 of groundworks. On a cheap bridge the move and civils can match or exceed the purchase price, so price the whole journey first.

Does a second-hand weighbridge need recalibrating?

Yes, always. Transport and reinstallation disturb the cells and their loading, so have it commissioned and calibrated with test weights on your own foundations before weighing anything that matters, and service it annually after that.