A bridge which is receiving maintenance work is stuck in place.
Kingsferry Bridge, which connects Sheppey with the mainland, is unable to lift for shipping to pass underneath it.
Network Rail is carrying out rope repairs which stabilise the lift mechanism of the 64-year-old bridge.
Built by British Rail in 1960 the bridge is used by motorists and pedestrians and is the only route trains can use to get across The Swale.
The last time the ropes were installed was almost 30 years ago in 1995 and have degraded and urgently need replacing.
The first phase of these works took place at the weekend when it shut completely at 10pm on Friday, June 7.
It is the first of a series of closures over the next two months.
Some eight counterweight ropes were replaced on the Sheppey side of the bridge and it reopened at 5am on Monday.
The first ships passed under the bridge around noon yesterday.
However, engineers have had “a problem” with one of the newly installed ropes which now “requires further work”.
A Network Rail spokesman said: “Unfortunately, we have encountered a problem with one of the newly installed ropes which requires further work.
“This additional work means we cannot lift the bridge for maritime traffic, whether leisure or commercial until repairs are made.
“Technicians are working as quickly as possible to find a solution and we will be keeping mariners up to date on the progress of the work.”
The next set of closures will last for nine days from Friday, June 28 to Sunday, July 7.
Further closures will take place from Friday, July 12 until Monday, July 15.
Another nine-day closure will take place from Friday, July 19 to Sunday, July 28.
All closures will start at 10pm on the first day and finish at 5am on the last.
A regular rail replacement bus service will run between Sheerness, Queenborough, Kemsley and Sittingbourne stations during the closures.
