Case Study 2 - Haverton Hill Sub Station
|Project Name||Haverton Hill Sub Station 132kV Upgrade|
|Requirements||Ducting for 132 kV, 66kV, 33kV and 11kV Electric Cables|
|Distance||Approximately 140 linear metres|
|Crossing||Containor Yard, Railway Line, Marshland and a 45 degree incline|
|Drilling Suggestion||3 x 3 way 160mm o.d SDR 11 Ducts (9 x 160mm total)|
|Constraints||Un-Accessable marshland, steep incline|
|Ground Conditions||Clay/ Silt/ Rock/ Concrete|
|Installation time||8 working days (7am - 7pm)|
SW Directional Drilling were invited by Murphy Pipelines to design a Directional Drilling solution for a multi duct installation across a busy containor yard, railway line, marshland and a steep incline. The ducts being installed were to upgrade the existing sub staition at Haverton Hill in Middlesbrough with the main cable being a 750m 132kV Feeder Cable. After meetings about the cables to be passed through the ducts and the route, we decided that 160mm HDPE ducts would best suit the purpose needed by the client, which they agreed(A larger duct size would normally be used for a 132kV installation but due to the constraints of the land and the width of the easement, the settlement figures would have been too high). After looking at the route via overhead and on site, it was decided that it would be wise to keep the drill as straight as possible as bad ground was expected and all the steering needed to be concentrated on height changes. The overall distance estimated by the overhead was roughly 140 linear metres. For this task SW Directional Drilling decided that a DitchWitch 30/20 Mach 1 would suit the task nicely and should have more than enough power whilst keeping the minimum footprint within the sub-station, which was crucial.
Below is a bore plan of the first drill, please click it to enlarge
Mobilisation and Commencement of Works
Once all method statements, risk assessments, bore plans and max settlement predictions were completed and passed by Network Rail, SW Directional Drilling were mobilised to site.
Daily description to come (9 Mar 2011)
Case Study by Chris Weatherall of SW Directional Drilling