Rema Tip Top Ireland provide steel cord and fabric belt installations and repairs for the Dublin Port Tunnel project.
The National Development Plan was drawn up by the Irish Government to implement large infrastructral works to improve access to markets and to increase quality of life for areas affected by traffic congestion.
As part of this plan, Dublin City Council entered into a contract with a consortium of Nishimatsu Construction Japan, Mowlem U.K. and Irishenco Irl., to excavate twin tunnels from Dublin Port to the North ring road (M1/M50), a distance of approximately 4.5km.
Reducing Dublin’s HGVs
The aim of the tunnel construction is to remove as many HGVs (Heavy Goods Vehicles) from the Dublin City centre area and direct them away from the very congested city road system. Approximately 9,000 trucks per day operate to and from Dublin Port and, through necessity, pass through the main city centre thoroughfares en route to other parts of the country.
The twin tunnels are currently under construction and the main construction site is situated at Whitehall, a suburb on the north side. An entry pit 60m in diameter and 30m deep was sunk and from here the two TBMs (Tunnel Boring Machines) began excavating.
The machines were christened by local schoolchildren, ‘Grainne’ and ‘Meghan’ (names from Irish folklore). ‘Meghan’ is a soft ground machine which is excavating northwards and ‘Grainne’ is a hard rock machine excavating the main tunnels north and south. The latter is an 11.82m diameter, 156m long, 1600t machine with a capability of excavating at 60mm per minute advance rate.
The TBM is connected to the pit by a conveyor system operating at max 980t per hour, a lump size of zero – 200mm, and a belt speed of 2.2m per second. The conveyor belt is an ST 1250 Conti, 1000mm, steel cord which carries all the TBM excavated material to the surface for disposal.
Rema Tip Top Belt Installations
This is where Rema Tip Top Ireland comes in. Rema Tip Top Ireland was chosen by Nishimatsu Construction Ltd to provide steel cord and fabric belt installations and repairs for the duration of the contract.
R.T.T. Ireland purchased two new Remapress K&K Hydraulic presses to carry out the contract and the already experienced vulcanising crew were given full in house, hands on training on the new presses prior to the job beginning. The training was carried out by the R.T.T. Munich Technical back up team.
It was decided for easy access and speed of operation that both presses would remain in the tunnel while the job progressed. This exclusive use of the presses allowed for very efficient start times when speed is essential. Rema Tip Top also designed and built special vulcanising tables to accompany the presses which again helped to speed the work and also to provide accurate and effective joints.
The TBM system incorporates a conveyor belt cassette holding approximately 300m of belt, which self feeds as the TBM advances. When the cassette reaches zero a new piece of belt 300m is inserted into the existing one and excavations continue.
However, because operating conditions tend to dictate downtime on the TBM, these stoppages provide windows of opportunity for inserts, repairs, service etc., so it is necessary for R.T.T. Ireland to respond at very short notice when breakdowns occur. The belt inserts involve two crews of three men operating simultaneously to instal the 300m insert by making two steel cord splices using both vulcanising presses. R.T.T. has been very successful in meeting this demanding schedule and to date all inserts and repairs have gone without a hitch.
The steel cord splicing kits used are manufactured by R.T.T Munich so the customer has the additional security of quality and compatibility of material from factory to end user. The kits are held in stock at their Dublin workshop for instant withdrawl.
The excavation of the tunnels is expected to be completed in June 2004 with a final finishing date for the total project of June 2005, when Dubliners will finally be released from the fumes, noise, and traffic jams of HGVs in their city centre and environs, a very nice prospect indeed!!! Rema Tip Top Ireland is proud of the part they played in achieving this goal.