TSL developed a model to inform a multi-modal construction logistics strategy for the tunnelling works in the Thames Tideway and Northern Line Extension projects. The project was commissioned by Laing O’Rourke in 2013 and was carried out over 12 months. The study sought to:
- Prioritise material movements using barges over the Thames (instead of trucks), therefore reducing emissions and the burden to the road network.
- Minimise the number of deliveries through consolidation and optimal choice of transport modes for the various material requirements.
- Support just-in-time deliveries, therefore reducing the need for on-site storage and minimising interruptions due to resource exhaustion and waste product accumulation.
The logistics environment in this study was governed by significant variations throughout the tunnelling projects, such as:
- Varying tide patterns, that would affect the ability of loaded barges to navigate under specific bridges and approach loading berths.
- Varying levels of traffic congestion over the course of a day, that could affect the timeliness of deliveries.
- Varying rates of material requirements and waste production, which were closely linked with a complicated construction schedule.
- Interaction between construction and material delivery processes, with where scheduling delays at either end directly affecting operations throughout the supply chain.
- Off-site production of tunnel linings in a centralised facility outside London.
Following a survey of the state of the art in logistics operations modelling, the team developed a bespoke simulation and network optimisation solution based on the TSL Delos platform. The resulting model had the following features:
- Visual representation of inter-site operational dependencies
- GIS model of construction and storage facilities and transportation links
- Schedule of construction activities across sites and phases
- Analytics performance dashboard with user-defined KPIs
- Interface with Metis, TSL’s bespoke simulation-optimisation library.