Pumping away :-)

Saturday already and unlike the rest of the week it’s been a little driech here to say the least. Not anything unusual for late November but the weather has been so good this autumn that we’re all taking to it quite badly. For heavens sake, I even had to wear my oilskins this morning to untie the ship. In nautical terms that would be ‘let go’ but if I’d written that then you’d probably have thought I’d passed wind.

Anyway, the week got off to a cracking start on Wednesday morning as I trundled down to work in the ‘Old Girl’ with all lights blazing. That two months ‘off the route’ has certainly seen the days on Raasay shorten.

I’d left the house early in hope of capturing the incredible starry sky but all I could come up with was this. Pretty lame I know but if you look carefully you can see Orion.

 

A day ‘at the pumps’

Wednesday  was a cracking day but I spent much of it down below working on one of our three ‘fire and bilge’ pumps.

 

BFP1 resides in the aft engine room and had developed a leak whilst in use, nothing crucial but boodly annoying because it leaked into the bilge which was then really awkward to dry out. At only a year in service and with very little use other than the weekly checks and drills a pump like this should not be leaking anything. It’s not like this is a regular Chinese or Indian piece of 5h1t, this is a DESMI pump, arguably one of the best and if you’d told me thirty years ago I’d be repairing Desmi pumps I’d have laughed. Aye, thirty years ago I was searching for Desmi pumps inside shipwrecks to weigh them in for scrap The company has been around since 1834 and is one of Denmark’s oldest manufacturing companies. They are also responsible for half of the church bells in Denmark From 1900 until 1970 the company also manufactured church bells, which was quite a unique trade. About half of 4,000 churches in the country were supplied with church bells from DESMI, and most of them are still in use today  Don’t you just love Google

It’s not a particularly difficult job and can be done with the pump in situ.

  

The first job being to remove the flexible coupling that connects the pump to the motor, this being held in place by an ingenious thing called a ‘Fenner taper lock coupling’. This type of coupling uses two grub screws to tighten a tapered sleeve onto the shaft and can be removed very easily by taking out the two screws then using one of them in another threaded hole to free the taper. It’s pure genius but the best way to see it is watch the video https://www.youtube.com/watch?v=fT4axK3haQ0&spfreload=10

  

These pumps rely on and expensive ceramic mechanical seal but this one was either poorly assembled or severely abused afterwards.

With the ‘centrifugal’ pump repaired and tested I then set about emptying the bilge of all the water I’d accrued in draining the pipework and pump. This time using a ‘progressive cavity pump’ https://www.youtube.com/watch?v=GaeLadH9sN8 more suited to sucking up dirty oil. This type of pump uses a worm that rotates within a flexible stator and is generally used on waste oil or oily bilge pumps. Only problem being that it wasn’t working

 

 

Here’s the rascal and this one was made in India, though it had failed through no fault of its own.

You can see the ‘worm’ (rotor) on the end of the pump and the flexible stator inserts at the bottom of the picture. The stator was obviously damaged through being run dry, probably as a result of having been inadvertently switched on. One of the switches used to be in a very silly place It was soon sorted and actually took longer to clean up the bilge than repair the pump. Hallaig’s large ‘flat bottom’ being very difficult to clean

The rest of the day I spent ‘topside’ making the most of the sunshine,

it was far too nice for grubbing about in the engine room.

Thursday

Another peachy day followed and this time I had the pleasure of the ‘wee dug’ at lunchtime, wifey having gone to Portree in Phoebe.

 

As Molly had been stuck in the Land Rover all morning I took her for a wee wander around the old pier. Whilst I used to often work out of here I seldom pass by these days.

It managed just fine without railings for a hundred years but these days people are a lot more stupid and lawyers a lot greedier.

What used to be a post belonging to a derrick has now acquired a lifebelt, in times gone by this was used for unloading coal and the like.

This, I believe was a set of scales once for weighing coal and stuff brought in by boat.

The old dock has benefitted greatly from the new harbour and now no longer fills up with rotting seaweed, at least not anything like it used to.

 

Whilst the ‘wee dug’ and I were wandering around this heron never moved,

they must have great balance, either that or there’s so much weed under that buoy that it doesn’t move.

Pig island with the heron barely visible in the distance, when my Panasonic works properly it’s a great camera.

Another DESMI

 

 

 

Well that was Friday night awaiting the last sailing and now it’s Saturday and I’m just digesting dinner.

 

A sumptuous affair of roast chicken, chips, gravy and cabbage, though I skipped that, I am not a cabbage person.

Today I repaired yet another pump, this time one of the auxiliary cooling pumps that circulate water around the 375kW ‘permanent magnet motor’ and Voith Schneider propeller unit. As with most of the systems on a ship there are two pumps so there is always one available in the event of failure or servicing.

 

This pump, pump 2 only had a very slight leak, evident by that spray mark on the bulkhead, however I was very much in ‘pump mode’ this shift so decided to change the seal. Like the bilge pump, it’s a centrifugal pump with a very similar mechanical seal, unlike the bilge pump however these are cast iron bodies. They are pumping fresh water with a corrosion inhibitor in it, unlike the bilge/fire pumps that pump seawater.

  

Judging by the black gunge and damage done to the seal this pump had very obviously been run without coolant. As this entire system was filled when Hallaig was built then it must have been done at the yard prior to commissioning.

Again, it was just like the larger pump, simply a matter of removing the bronze impeller, old seal then cleaning up the shaft and carefully fitting a new seal. A new gasket fitted and then the motor and impeller lifted squarely onto the pump body, though not in line with the studs.

 

It was far easier to make the electrical connection with the motor 45 degrees anticlockwise, then drop the motor onto the studs after.