Floating pontoons being delivered to Queenborough had to be recovered after they came loose from a tug boat and drifted away.

The three 16m by 20m platforms were being towed from Portsmouth to Sheppey, where they will be used by Queenborough Harbour Trust (QHT) to extend the all-tide landing and provide more spaces for moorings.

Dover Coastguard received a call about 4.50am last Wednesday from the tug boat, operated by Thames Towage Ltd, to say two of them had detached between Dungeness and Ramsgate.

A warning was broadcast to nearby ships to look out for the adrift sections and they were located by the radar of two passing ships.

The coastguard arranged for another tug boat to come out to collect them and take them to Dover, where they are waiting to be collected so they can finish their journey.

The other section which did not detach continued on its journey to Queenborough.

Stuart Bradley, a director at QHT, said: “We hope that the errant sections will be with us this coming week.

“It will be delayed but not by a significant amount of time. I can’t see it being more than a fortnight.

“We are just annoyed that we are going to be delayed by a couple of weeks but the way nautical things go, we don’t own them until they get here.”

He added the trust has not lost any money over the incident.

The setback means the planned transfer of QHT’s seafront office from Crundells Wharf onto one of the platforms could take slightly longer.

Sittingbourne-based WPH Marine Construction, the civil engineering firm employed by the trust to oversee the new pontoons, which contracted out to Thames Towage, said an investigation is underway but declined to comment further.

On Monday the tug Svitzer Warden came to bed in anchors to keep the incoming pontoons in place as a favour to the trust.

First mate Andy Jacobs said they were only able to bed one in place, however, and they might need a smaller vessel to do the remaining ones because the size of the boat meant it was, “a bit like using a sledgehammer to smash a walnut”.