The SAS13 bridge replacement project was situated near Birmingham City Centre and acts as an enabler for HS2 on behalf of Network Rail. The bridge comprised of eight masonry arches and a central steelwork span that required demolishing and replacement by a 92-metre single-span steel structure. The works paved the way for the construction of the new HS2 line approach into Birmingham City centre and the planned HS2 Midlands Maintenance Depot.

Key features:

• Rigorous design and early works

• Complex bridge demolition

• Interface with Network Rail and HS2

• Lifting of steel bridge   

• Delivery of a 2nd lift as part of enabling works on behalf of Skanska

This technically and logistically challenging project was led by our senior projects team, all of whom are experienced in the specialised elements of major rail projects, coordinated lifts and bridge removals. As standard procedure, Armac conducted extensive pre-lift analysis of the steel bridge to ensure the structural integrity could be assured as the crane lifted the structure. Lift designs were managed in-house by our technical team, who along with their experience on similar schemes, hold CPCS categories as ‘Appointed Person’ and ‘Lift Supervisor’.

Armac’s owned and maintained, industry-leading fleet of demolition-specific excavators means we were in a unique position to deliver the firepower and resources to achieve accelerated programmes.

With surgical precision, Armac separated the brick arch structure from the steel bridge, exposing the bearings at either end, allowing the lift to commence. The methodology initiated by our experienced team resulted in the safe and precise lowering of the steel span to ground level where it was dismantled and removed from site. With the steel bridge removed, the attention was pivoted towards the eight segmented, masonry arches. The deck and piers were dismantled using 8, 40 tonne-plus excavators. Hydraulic hammers were used by our highly skilled operators to progressively fracture the structure until all remnants had been removed right up to the embankment of the new bridge.

The project team robustly evaluated the operational logistics such as plant mobilisation, de-mobilisation, and waste removal, ensuring minimal disruption to the local area in line with our clients KPI’s. Short duration schemes with the additional pressure of scheduled and unmoveable follow-on operations can be challenge to inexperienced contractors. Understanding the client’s needs and our experience on similar schemes reduced any pressure and positive outcomes were achieved. To assist in meeting the short programme times, material was loaded out as it was produced and removed from site by our locally sited logistics fleet to a separate facility. Once at the facility it was further processed and crushed to 6F2. Conducting this efficient removal of waste was an important process that allowed our client to mobilise and set the site up for the new bridge installation.

Due to Armac’s extensive experience with lift design and having already successfully coordinated the initial lift out of the steel bridge, Armac were requested to perform additional enabling works. Two precast end plates were lifted into place with millimetre precision by our technical team. This positively benefited Skanska’s programme time as the need for a separate lifting team to be subcontracted-in was rendered redundant. The overall outcome had positive and monetary and programme time benefits.