Day 26 - 6 October

The sixth week is a key one which sees the removal of the last remaining working parts of the mechanism, the multifunction cam and the fusee. These are in effect the ‘heart and brains’ of the mechanism, which allow the graceful movement of the Swan’s head and neck.

Matthew and Karen will remove these from the centre of the mechanism and will take them apart. Once they have been lifted out, all that will remain of the mechanism will be the brass frame and the neck and bill of the Swan.

We do not know at this stage what condition the cam wheel and the fuse are in or how contaminated with oil they have become. They contain internal springs which will be inspected for wear and damage. When these are opened up it will also be clear when it was they were last cleaned. This may have been during the conservation work in the 1970s or it could be that they may not have been examined for significantly longer than that.
It is obvious that the main wheel, which should remain dry, has oil residue between the cogs and needs thorough cleaning.

Day 27 - 7 October

Yesterday saw the removal of the main driving movement which allows the head, neck and fish to operate.

Matthew was able to dismantle ‘the brain’ of the object and remove all the cams that are piled on top of one another within it. The cams are the pieces that enable the different movements, from the nodding of the head to the arching of the neck.

The most time consuming job was the removal of the zig zag cam. This is the part that rotates the neck. Once all the pieces were eliminated Matthew discovered that there are at least twice as many holes piercing the cam than are in use. He has found that this part is hollow rather than solid and so when last washed water seeped through the holes, creating a sludge inside which will have to be cleaned.

Today, Matthew and Karen will start to clean and photograph the 50 parts plus screws that make up the main driving movement.

Day 28 - 8 October

Yesterday Matthew and Karen cleaned and documented most of the parts of the ‘brain’ that was dismantled from the main driving movement on Monday.

The main plate of the zig zag cam which operated the Swan’s neck was taken apart and as suspected was full of sludge accumulated since the 1960’s restoration project.

Today will see the rest of the parts cleaned. Matthew will then move onto dissembling the main movement, which will allow for the first ever look at the Springs.

Day 29 & 30 - 9 & 10 October

The conservators are continuing to clean the main driving movement for the neck. This comprises plates and pillars which form the outer frame, with the spring barrels inside.

The frame is a bespoke piece made specifically for the mechanism and one of the largest of its type. It is however, no thicker than a good quality bracket clock of the period though the makers made the bearing surface wider by work-hardening the plate in order to add strength to support the weight it is carrying. A bracket at one end is evidence of a subframe having been added, possibly because during the process of testing the mechanism, it was discovered that it was not powerful enough and an additional spring barrel had to be added. There is evidence on the plates at either side of the frame that the barrel and fusee were originally located in the wrong place – plugged holes show where they were first placed.

The two barrels each contain two springs. These are about 1mm thick making them each about 20 times stronger than a domestic bracket clock of this period – these are the real powerhouse of the mechanism and capable of creating an immense drive.

How these springs are extracted from the barrels is going to demand Matthew’s most creative ingenuity. As he says, dealing with these is going to take him from the realms of clock-making and into engineering!

For a full BBC INside Out film of the Silver Swan please click on the following link:   http://www.bbc.co.uk/mediaselector/check/england/realmedia/insideout/northeast/090114_io_north_east_swan?size=16x9&bgc=C0C0C0&nbram=1&bbram=1&nbwm=1&bbwm=1

To be kept informed about The Bowes Museum please click here