Archive for the ‘Kennet & Avon Cycle Route’ Category

WWII Pillboxes: Kennet & Avon part 5

Sunday, September 27th, 2009

The southern English countryside is dotted with thousands of small but substantial WWII fortifications.  Of the 28,000 pillboxes built to defend Britain from German invasion, approximately 6,000 of them are still in place.

WWII pillbox

Expecting imminent invasion, the UK put  huge level of effort into the construction of anti-tank and defence lines across Britain.  Churchill had originally planned a series of three defensive lines across the southern part of England.  The Kennet & Avon Navigation, along with the Thames, provides an unbroken wall of water across the entire southern length of England, from Gravesend through London and Reading to Bristol.

Large Pillbox

I encountered the first of many small pillboxes just beyond the weir at Hamstead Lock, where the cycle route rejoins the canal towpath.  Most of these were made from poured concrete.  Several larger ones are made, at least partially, from brick. The one above is just outside of Newbury.

Crofton Pumping Station: Kennet & Avon part 4.

Wednesday, September 16th, 2009

Croften Pumping StationThe Crofton Pumping Station has the oldest James Watt steam engine still operational (installed in the pumping station in 1812). Just below the highest point of the canal, the station was located near a source of water, which it raises about 40 feet and dumps into a 1 mile long feeder which fills the canal near Bruce Tunnel. Today, the canal is fed by electric pumps, although the steam pumps were used as the primary source of water during a mechanical outage earlier this summer.

Lancashire Boiler

The station operated under steam until 1959. Volunteers spent about 30 years painstakingly restoring 2 steam engines, the Lancashire boiler shown above, and the facility. Restorations were completed in 1997 with the topping out of a rebuilt chimney (top photo).

Valves and Cylinder Head

The photo above was taken in the cylinder head room.  The piston rod is at the far right side, leading to the beam gallery overhead.  The three round things in the background are the valves which control the flow of steam into and out of the cylinders.  They are operated by connecting rods coming down from the overhead beam.  The photo below was taken in the well head, looking down towards the water level. It shows one of the two 30 inch bore, 8 foot stroke pumps, and the connecting rod coming from the beam above. The large cast iron pipe in the upper right leads to the launders, where the 1.25 tons of water is discharged on each stroke.

Well

Additional photos can be found in my Crofton Photo Gallery.  Below, you can see the route I took from The Upper Westcourt B&B to Crofton.  Zoom in and use the satellite view to see the pumping station’s relationship to the canal and the feeder canal (upper left of pump house).

Claverton Pumping Station: Kennet & Avon part 3.

Tuesday, September 15th, 2009

Claverton Pumping StationEvery time a boat transits a lock, a huge volume of water runs downstream.  Canal engineers struggle not only to ensure adequate water to supply the locks, but they also need to compensate for leakage, which turned out to be especially critical in the stretch of canal between Bradford and Batch.  Chief Engineer John Rennie came up with the solution of putting a pumping station at Crofton.

Unlike the steam powered pumping station at the canal’s peak in Claverton, this pump would be powered by the current of the Avon River. Volunteers have completely restored this facility, putting it back into working order.  Just a few miles out of bath, this was the first stop on my weekend cycle tour of the Kennet & Avon.

Waterwheel

Claverton’s waterwheel is a type of breast wheel in which the water flows into the side of the wheel, and continues underneath it. Less efficient than a pure overshot wheel, it makes better use of available water power than does an undershot wheel. With its iron frame and wooden paddles, this wheel is 24 feet wide and 17 feet long.

The Pit Wheel on the left (below), a wheel composed of cast iron sections with wooden teeth, is directly connected to the axle of the water wheel.

Transmission

It drives an iron-toothed gear wheel on the right which is mounted on the same axle as the flywheel and connecting rod.

The connecting rod oscillates a pair of large beams which are connected to a pair of pumps.

In order to keep the pump cylinder rods straight, a clever mechanism called a Watt’s Linkage is used.  This same mechanism was a common feature of 19th century pumping stations, and can also be seen at Crofton and Crossness (photo gallery appearing here soon).  One of the pump cylinder heads is shown below, in a picture taken from below the beam.

Watt Linkage and Pump Head

More photos of Claverton can be seen in my gallery.

Kennet & Avon Canal Cycle Route Overnighter: part 2

Friday, September 11th, 2009

Steep hill climbe up a tree-lined lane in FroxfieldI took my time over breakfast and the Sunday paper with Peter & Carolyn at the Upper Westcourt B&B, leaving about 10am for the 15 minute ride, arriving at The Crofton Pumping Station well before it opened (blog posts on both pumping stations coming up shortly).  Unlike the day before, it was still sunny after this day’s  industrial heritage stop.

The first half of today’s trip would still follow country roads, before rejoining the tow path, but looking at the map, they didn’t diverge as far from the canal, and at least seemed to be less steep.  It turned out that I had multiple opportunities to practice coasting, preceeded of course by the obligatory climb.

Like Saturday, the first half of the trip was characterised by attractive country towns, like Great Bedwyn, and pretty villages, like Little Bedwyn.

The biggest town of the day was Hungerford, which under other circumstances would have been worth a longer stay. On the far side of Hungerford, the road crossed a cattle guard and a gate, and I entered the Hungerford Common Portdown.

Hungerford CommonsThe commons is a 200 acre shared pasture.  I stopped to take some pictures, and watched a farmer walk out to check on his cows, all of whom seemed to have a healthy suspicion of  the road (in spite of the nominal 30mph speed limit).

Kintbury

Kintbury was the last town before rejoining the towpath.  Many of the buildings were built directly on the narrow High Street.  I stopped to take a picture of my bike in front of a colorfully named pub, and then continued on, finally rejoining the canal and towpath at Hamstead Lock. The path was much narrower and yellower than it had been at the start of the trip in Bath.  In many places, it wasn’t wide enough for 2 bikes to pass between the nettles and the canal.

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Kennet & Avon Canal Cycle Route Overnighter: part 1

Wednesday, September 9th, 2009

Pulteney BridgeLast Saturday, my loaded touring bike and I caught an 0813 train to Reading, from whence we continued on a fast 1 hour trip to Bath in Wiltshire. I waited outside the station for my GPS to get a signal, and then I took off into the Saturday morning traffic in this busy tourist town. My goal was to complete the entire Kennet & Avon Canal Cycle Route, which ended 85 miles later, on the other side of a ridge, in Reading, Berkshire. The route crossed the 1773 Pulteney Bridge, which is lined with shops. After about 10 minutes of cycling, and only one wrong turn, I crossed a short bridge, and turned onto the canal tow path. From here to Devises I’d be following a fairly wide and level path, for the most part smooth and well-graded.

Bradford Tithe BarnIt was a beautiful, sunny morning, and I stopped to take off my jacket. After a very pleasant 25 minutes of easy riding through the lovely Wiltshire countryside, I reached my first stop, the Claverton Pumping Station (described in an upcoming blog entry). What I expected to be a rather short visit turned into an almost 1 hour stay. Noticing that the sky was darkening, I begged off the video portion of the tour, unlocked my bike, and pedaled up a steep hill back to the canal level.  During the next several miles, I crossed two very spectacular aqueducts, the Dundas Aqueduct, which was next to a wharf with small crane, and the Avoncliff Aqueduct.  I continued on to Bradford, where I stopped briefly at the early 14th century tithe barn.

Caen Hill Locks In a 2-mile stretch between Foxhanger and Devises, the canal rises 237 feet, for a 1 in 44 gradient. Chief Engineer John Rennie dealt with the steep rise at Caen Hill by building a set of 16 locks in a row. This is considered one of the most significant engineering achievements on the entire British canal system, and in contrast to the Ratty & Mole ambience of much of the waterway, it makes for a dramatic feature.  It requires a lot of water to fill up a lock. In order to ensure enough water for this aquatic staircase, Rennie excavated large basins extending sideways (to the left in the photo above) in front of 15 of the Caen Hill locks.  I rode up the steep hill, passing several bikers who decided to walk, stopped to take a few more pictures of the ponds and narrow boats in the lockes, and then headed into Devises.  It was almost 2pm, it was starting to drizzle, so I asked for directions to a pub. Riding into the center of town, I stopped at The Castle Hotel for a lunch of cottage pie and a pint.  The proprietor of this 18th century pub let me park my bike indoors.

After lunch, I wound through town looking for the Cycle Route. After 10 minutes of what seemed like endless wandering through housing estates, I was suddenly confronted with a steep hill leading down to the canal and its narrow tow path. I walked down. After less than a mile, a sign for the Cycle Route pointed up a steep incline away from the canal. I decided to tough it out, and ride up. It was going fine until I reached the top and had to immediately stop. Fortunately, there was a bed of stinging nettles to catch me.

Ascent in EtchilhamptonDevises is nearly at the top of the canal, and after 22 miles, I naively thought that I was done climbing for the day. The reality was that I would spend the next 24 miles zig-zagging from one side of the Vale of Pewsey to the other, crossing the canal and railroad multiple times.  I climbed to the top of a ridge, where I had a fantastic 360 view of the mostly harvested fields and the ridge far to my north, which included one of Wiltshire’s famous white horses.

After Pewsey, the terrain become a bit more closed in again, with increasingly narrower roads, usually surrounded by hedge rows. Outside of Oare, the road chosen for the cycle route was barely a car width, and it had a light median of grass and gravel. It was also closed to traffic. A road closed sign is either a biker’s dream, or nightmare. I chose the former, and it turned out OK, leading me between beautiful farms with thatched roof houses, usually built on a timber frame several hundred years ago.

Especially after a hard climb to the summit, there is something thrilling about coasting down a long, windy, steep hill, hedgerows full of bramble and barbed wire whistling past your ears as you enjoy the sensation of speed and wind, and idly wonder just what you are going to do if the next turn confronts you with a fully loaded farm vehicle, or just an especially slippery patch of gravel.   I ended up taking a similar opportunity descending a steep road into the terminally charming village of Wootton Rivers.  In this case, it was actually only a Volvo, but given the deeply eroded ditch at the side of the road, it was more than big enough to test the emergency stopping abilities of the Kool-Stop brake shoes. They worked, and everyone came through the event intact. I had to prematurely terminate more than one long coast just in order to follow the bike route.

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