Holdfast Training Services Trial Blog

A combination of Imran leaving and some of the other SPAs being on holiday have contrived to make my life considerably busier, but in a good way.  I have now taken over all of Imran’s tasks, the HP Cooler Replacement, the Minox Blower, Flowline Supports and the closeout of LP and MP Cooler Replacement from 2013.  On top of this, I am still responsible for the Retrofit of Cabins and I’m intrinsically involved in the Lifeboat Modifications.  I’m not going to touch on all of these areas, just the closest crocodile, which is a problem with a flushing skid for the lifeboats.  I would appreciate any good ideas that may be out there.

The Detail

This job has not gone smoothly, it has had problem after problem and nearly all of them could have been avoided.  The latest issue involves a flushing skid, which is a piece of equipment used on hydraulic equipment to clean the components and test the system.  For the lifeboats job we are recertifying the davit A frame, which is used to recover the free fall lifeboat from the water if necessary but on Clair the davit and A frame have not been used in 9 years.  Anyway, the flushing skid required has to meet certain criteria in order to adequately flush the system, in this case it needs to produce a Reynolds number in excess of 4000 and NAS of 6/7 but not to exceed 7.  The job is due to start on 7 Jul, with the skid required in early Aug and a skid has been procured and been shipped offshore.  The flushing skid that has been procured has a motor with the following ratings; 37kW/400V/50Hz and 43kW/460V/60Hz. 

The platform conditions are 440V and 60Hz so a fair assumption is that the power output is closer to 43kW than 37kW.  Depending on power factor and efficiency of the motor, it could draw up to 78A.  I do not have a data sheet for the motor so I have assumed 0.85 for both.  I have approached the manufacturer and vendor and requested the data sheet.

The flushing skid starts using star delta and as such it requires a 3 phase and neutral supply.  The problem is that the platform only has a maximum of a 63A, 3 phase welding point from which to power the skid.  Since it is the SPA in charge of this job in on holiday I have been left to try and resolve the issue and I am trying the following three options.  If anyone has any better ideas then I’m all ears:

• Install a temporary JB and use a single cable from this to hook up the flushing skid once it is in place.  Then, detach the cable, move the flushing skid to its second location and hook the downstream end of the cable back up to the flushing skid again.  There is a switchboard that appears to have a spare cubicle, it looks like it has 3 phase and a neutral and is capable of taking 200A.  However, there is conflicting information because the platform as built shows no neutral but the ABB as built shows a neutral. I have requested that the REP offshore checks what’s inside the switchboard and get accurate information.  I sense this will take a lot of time and effort because it will require workpacks, isolations, method statements, a temporary electronic management of change, cable calculations and the procurement of materials.

• Get a new skid with a motor of a suitable rating to be able to be powered from the 63A welding socket and yet supply enough turbulence.  This is my preferred option.  It sounds the best on paper but I have no idea whether a suitable unit even exists.

• Source a suitable generator to power the flushing skid.  It sounds a bit like overkill to get a generator for one flushing skid, and there may be problems with exhaust fumes and footprint depending on size of generator.  That said, I know I’ve got a flushing skid that works already offshore so this is just the other half of the equation.

Since time is tight I have decided to pursue all options with equal measure and try and get a solution asap.  I wanted to avoid holding out for option 2 and then find out it’s not viable in a week’s time.

What is frustrating is that this machine was released by OIS, an inspection vendor, as safe to use.  This is the second time on this project that an electrical engineering problem has slipped through the net and caused problems further down the line.

In other news…

Brendan and I had to help out at Banchory Beavers Summer Camp.  All I can say is that Brendan is bottom of my prospective babysitters list.  He was beasting 6 year olds and at what point said “Listen in means you stop talking and listen to me or Nick.  Oi chap, do you have a problem?”

Imran’s leaving do was a success.  He got so drunk he lost his keys and slept outside.