Background to specification
Early in a number of Airfield pavement projects in Dublin Airport’s €2bn capital development was the bypass taxi-way codenamed MIKE 2. The drainage system had to be designed to the specific traffic expected airside at Dublin, with the Boeing 777 having the highest wheel loading.
It was due to be fitted with a concrete drainage system, but based on past experience of installation times, handling, convenience and cost, the main civil engineering contractors C&M Construction recommended a Tubosider corrugated steel solution.
The original design was for a 1500mm diameter concrete pipe system in three legs with four chambers on each run, the chambers interconnected by 700mm diameter pipe to help the flow between runs. Tubosider’s design called for a 1400mm diameter pipe system, giving a significant saving on transport costs alone. Nearly 30 more 40ft trucks would be required to deliver the same system in 1500mm concrete pipe.
Steel 1400mm pipe weighs only 460kg a 7metre length, whereas 1500mm concrete pipe weighs over 7 tons per 2.5metre length – around 35 times heavier. A concrete system would also require a concrete slab poured directly over the pipe to increase its strength, whereas with its high loadbearing capacity, the Tubosider tank uses only granular fill compacted in layers up to the apron build-up.
Solution & benefits
With a 1442 cubic metre capacity, the Tubosider stormwater attenuation tank & pumping station took only about a week to install on a prepared trench bed, being loadable immediately. Very few men and no heavy lift equipment were required.
The jointing systems allow two men to fully seal a joint mechanically in less than 20 minutes, and with Tubosider’s fast thread bolting system, this can be completed in as little as 10 minutes by an experienced fitter.
The chambers have a 1200mm shaft complete with ladder for access, all fully fabricated, and a large pumping station of 2.2 metres diameter and 4.3 metres depth with duty / standby pumping systems operated by complete control and monitoring systems.
Following the MIKE 2 project, Tubosider completed contracts for a smaller system for the New City Jet Hangar, followed by the Apron 6 Project with Clare Civil Engineering and further projects with Balfour Beatty Ireland.