Congleton Hydro Newsletter June 2021

Wot! the Access Track has disappeared.

Access Track filled in with “spoil” from construction.
Now we cannot go backwards—only forwards!!
 

However, before the slippery downhill slope started its return to nature and the access track across the field was returned to its rightful owner, they had one more duty to perform ——- enabling the transport to site of the Control Cabinet, Gearbox and the all-important Generator (well, all the bits and pieces are important but it’s the Generator that does the work of converting the fluid power of the river via the mechanical power of Archie the screw, into the crucially important Saleable Electrical Power). What a day to choose Friday May 21st…Congleton Monsoon!! But a resourceful digger with an expert driver saw them safely delivered.

The weather was so bad that photographs were difficult to produce (wet and muddy fingers are not ideal for operating the camera function on smart ‘phones!!), however one of our intrepid team managed to chart the progress of the Control Cabinet, full of delicate electronics being safely delivered.

Fingers Crossed for safe delivery of the Control Cabinet.

Of course, this would all have been a fruitless activity if we did not have anywhere to put these three precious items. One of the last jobs of CT Construction before leaving the site was the completion of the Powerhouse. You may recall from the last newsletter that we were frustrated by the availability of bricklayers and scaffolding and especially the synchronisation of the two!!! Finally, it all came good and as you can see, we have a Powerhouse.

Powerhouse (to be fitted later with wood cladding)

From now on, the only means of access to the Hydro site is via the Boardwalk. Even though still frustrated by availability of materials (seems to be a worldwide issue for many building items—Toilet Rolls are now ex-stock but timber and even screws are on extended delivery!!) Jim and Colin of Redfox have made excellent progress with the construction with basic access now available from Havannah Lane right through to the Powerhouse entrance.

With the Boardwalk essentially structurally completed, it was now time to install the final section of the “Export Power Cable” (the approx. 1KM buried link from the Hydro to Eaton Bank). The team from Duttons did an excellent job jointing the cable and pulling it through to the Powerhouse. To aid the task they used the strength of a small (1.5ton) digger and as you can see from below this gave the boardwalk a great structural test—passed with flying colours!!

The cable joint, whilst looking simple is not easy but a highly specialist job. The person doing it had learnt the trade from his father, who in turn had learnt it from his father The jointers young son was on-site as he is also going to follow the family tradition. When the joints are complete, the “box” is filled with a special resin that has extremely high insulation properties and of course is waterproof. Now buried, the joint will have a lifetime of 100+years.

The cable is now terminated in the Powerhouse and a suitable breaker switch installed to connect/isolate from the Customer (Siemens) at the other end. The whole cable installation will now be tested for continuity and impedance (hopefully very low!) and insulation (hopefully very high!). Via the Powerhouse breaker, the cable will be connected into the variable speed drive in the control cabinet. This, together with the associated control system hardware and software will control and optimise the “power train” – Archie and generator output. Whilst the detailed operation has been covered in a previous newsletter technical attachment, we will include a simplified single line diagram of the electrical system in next months newsletter (it should all be connected by then!!) As you can see in the photograph of the cable incomer arrangement, being competent professionals (well we think we are—and our peers have judged us to be!!), we are safety conscious but just in case, First Aid kit and fire extinguisher are to hand.

The eagle-eyed amongst you will say “hang on, that’s not a 300mm cable”. You will be correct, you will then hopefully recall from a previous newsletter that the final 40metres or so of cable is 95mm copper, (transition from 300mm aluminium to 95mm copper is via another cable jointing arrangement.

Export Cable Incomer and Circuit Breaker in Powerhouse.

The last week of May has seen the uniting of Archie with his stablemates i.e. The Gearbox and Generator. As a reminder the gearbox is used to transition Archie’s comparatively low-speed rotation to the higher speed requirement of the generator to achieve its output voltage and frequency.

The installation was carried out using the specialist services of RMS (Rotating Machinery Services) from Stoke on Trent.

Initially, all did not go to plan. In last month’s newsletter we covered the installation of an “A Beam “on which suitable pully hoists would be attached to lift the gearbox and then the generator into position on the pedestal. The rated SWL (safe working load) of the A Frame is 1000kg—ample we thought. However, when the rating label attached to the gearbox was checked, it stated the weight was 1350kg—consternation and panic—how did we get this wrong? how would we proceed without major impact on timescale and cost (new A Frame? —but how would we get the old one out, let alone a new one in?).

Quite often major problems end up with complex solutions but sometimes the solution can be dead simple and quick—and lucky we were! The rating label on the gearbox was incorrect, we had forgotten that for its original design application, it had included an oil cooler system, we were not using this, and it had been stripped out, so phew – disaster averted but No! not quite, we were still overweight. Again, a simple solution, remove the top cover (no mean feat as it was secured by twelve M16 bolts, torqued down tight), this we eventually managed and with a weight of 1007kg (just a fraction over the spec) the lift and install could proceed. RMS are experts at this kind of work and their expertise was a joy to watch.

With top cover removed, Gearbox internals can be seen.

The generator and disc brake were next to be installed and the complete “train” can be seen below.

Archie, Coupling, Gearbox, Disc Brake and Generator installed on Pedestal
 (gearbox top cover not yet refitted).

In the background can be seen the control system cabinet.

The disk brake operates just like on your car. A “Disc” is fitted onto the output shaft of the gearbox and a pair of “disc pads” then sit either side. In normal operation the pads are not touching the disc but under braked conditions (either operational or emergency) the pads—just like in your car, come together, and clamp the disc. We will cover the operation of this braking unit in next month’s newsletter.

Archie will never have a 100% smooth rotation and as such there will always be some form of small “wobble” of his output shaft. As the input shaft of the gearbox is fixed, we use a flexible coupling to join the two together (the universal joints and mounting bushes used on your car have similar functions).

Flexible Coupling between Archie and Gearbox

We had hoped in this newsletter to give you an update on the Education Programme. Unfortunately, it has not been possible to adequately write this, mainly due to people being on holiday or other commitments, this does not mean work has not been proceeding and we promise that a full update including the STEM Schools project of “Generating useable Electrical Energy from a bucket of water” (this should whet your appetite!!) will appear next month.

So, the last weeks has seen excellent progress on the core project. Over the next few weeks, we will be continuing to wire up the Powerhouse (including sockets for kettle and toaster!), connecting the various sensors to the control system e.g., gearbox bearing condition monitor, input, and output water levels and so on. We hope to be able to have some form of test generation maybe by early next month.

Work still needs to be done to completely finish the boardwalk, install safety railings, especially on the water intake structure, cladding of the powerhouse, site security and particularly the security of the boardwalk entrance.
As always, we hope you have found this newsletter to be informative and of interest. It is intended to give you a picture of how the scheme is progressing and now coming closer to fruition. We would welcome your feedback and suggestions for any topics you might like to see in future issues. Please drop us a line at info@congletonhydro.co.uk

A note for Members/Shareholders. You will receive a separate email regarding proposed arrangements for the AGM to be held towards the end of the month.

As always: Please Stay Alert, Take Care and Stay safe.

P.S. We have an opening for a volunteer! The role is for an Admin Assistant, the purpose role is to devise and introduce a structured system that will enable the collation, production and maintenance of the historical design and operating documentation for the Congleton Hydro project.

If you fancy joining the team please view the full description HERE.

Contact info@congletonhydro.co.uk to register your interest!