Shaft sinking
Manningtree Station Lift Shafts
Two lift shafts for step-free access, sunk by hand excavation and hydraulic jacking within hoarded working areas on the existing platforms of an operational station.
The challenge
Lift shafts had to be constructed in a constrained station environment, linking the platforms to the existing subway while maintaining separation between the works and railway users. The original brief proposed rectangular caissons approximately 6m deep, with the shaft walls forming part of the permanent works and new passageways connecting to the subway.
Our role
Through Delta Civil Engineering, our team developed the shaft-sinking approach using our jacking system, with hand excavation inside hoardings on a live platform.
Design and method
Hand excavation and hydraulic jacking formed the construction method. The design package addressed the concrete collar, steel cutting shoe and jacking beam arrangement. Bespoke formwork details addressed the casting of shaft sections, and correspondence identified a temporary working floor for incorporation into the Work Package Plan.
Safety and site interfaces
Hoarded work areas separated shaft operations from the live platform, with passenger routes, secure boundaries and controlled access central to the working environment. Railway access, isolations and the interfaces with the existing subway were planning considerations, alongside coordination of design, construction sequence and station operations.
Project record
Records identified in the project correspondence include the RNP design calculations and drawings package (15148/001, issued 18 December 2015), Network Rail Forms F002 and F003 in the engineering submission, and the Work Package Plan with January 2016 review of excavation arrangements and supporting RAMS. The forms evidence the assurance process; final signed Network Rail acceptance is not reproduced or asserted.
