A partnership between the Woodland Trust and the National Trust

Holding tanks and penstock sluice controls

Water Power!

If any of you have walked a mile or so up the Teign from Fingle Bridge, away from Fingle Woods and onto the Castle Drogo Estate, you may have come across the weir which lies beneath Castle Drogo.  You may have watched salmon leaping up the weir in the autumn, usually a day or two after heavy rains have swollen the river. You may have enjoyed the water cascading down from level to level before dropping back into the main flow…but have you ever wondered what it was built for?

The River Teign is ideal for water power. It has a steep gradient as it flows past the castle, which means a good head of water can be generated even over a short distance. This basically means lots of free power! This power has been used for many hundreds of years to drive watermills that grind feed for animals and people and sharpen tools. There is another weir a few hundred yards from Fingle Bridge and the ruins of an old mill just downstream to prove it.

Julius Drewe, a self-made man, began building Castle Drogo in 1911, and following examples from men like Armstrong at Cragside House and local examples near Chagford, he chose to install a hydroelectric turbine on the Teign to ensure his house would be supplied with electricity.

The weir up which the salmon now leap was created to generate a head of water to run his turbines. From this concrete structure, built around 1928, a large pipe runs down through the woods to an unusual building which, like the castle, was designed by Edwin Lutyens and was supposed to look like a woodland cottage. Here, large tanks collect the water before it flows through the turbines and returns to the river. There are two turbines, a small one and a large, which ran alternately (but not together) depending on the flow of water, generating DC current which flowed up a very large cable (which was mostly only just buried) up to the castle.

The turbines ran from the late 20’s right up until they were decommissioned in the 90’s after one developed a fault. At the time it was cheaper to get connected to the mains than repair the turbine.

Last week we received the exciting news that after many years of standing idle the National Trust has permission to repair and recommission the hydroelectric plant so it will once again generate power. Next year we are going to restore the turbines to working order, the existing equipment will be refurbished and used wherever possible: new screens will be fitted to keep out debris; new generators will be installed; new power cables will feed power to the visitor reception building to power our shop, catering and visitor services operations. The grid in the south west is accepting no new power connections, so any power over and above what we can use will be used to help out the biomass boilers (which will also be refurbished as part of the project) to heat both the visitor buildings and Castle Drogo. All this work will be completed before autumn of 2017. With a revamped Biomass system and a functioning Hydro scheme we should be well on our way to being the greenest castle in the land!! Watch this space for more information over the course of the project.

By Tom Wood, Area Ranger for the Castle Drogo Estate, Teign Valley and Fingle Woods.

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