Details of a route for the main new Upper Orwell Crossing in Ipswich are expected to be published early next year as groundwork testing increases.

The ground investigation works, which could last up to three months are scheduled to begin on 15 January 2018.

Contractors Fugro GeoServices Ltd will dig trial holes and deep boreholes on land and in the water.

The works will determine the underlying properties of the ground and river bed. Engineers will analyse the information and use it to design the foundations on which the bridges will sit.

Land-based work will take place between 7am and 7pm Monday to Friday and 7am and 1pm on Saturdays, while the work in the water will be carried out 24 hours a day, seven days a week. Noise levels will be monitored closely.

There will also be a period where samples are required on pavements and roads – this work will not be carried out during morning and evening rush hours.

County council leader Colin Noble said: “These investigations are a significant step forward for the Upper Orwell Crossings project and demonstrates our commitment to deliver this major infrastructure project.

“This work will help shape the design of the three bridges, which our project team is currently working on with architects Foster + Partners and consultants WSP.

“These designs will be presented to the public ahead of the formal consultation in autumn 2018.”

Members of the public who live near to the ground investigation works can expect to receive letters informing them of the process before Christmas.

The timeline for the crossings is still on track and the council expects to start construction of the crossings in 2020 with completion scheduled for 2023.

Ipswich MP Sandy Martin has not received many representations from residents about the work so far – but does expect to hear concerns soon.

He said: “This will affect a significant number of people in the Old Stoke, Waterfront and Rivers Estate area. But however many affected by this work will be a much smaller number than would be affected if the bridge is ever built.”

He said he remains doubtful about the viability of the Upper Orwell Crossing bridge and is hoping to discuss it in meetings with senior council officers early in the New Year.