Sunday, January 23, 2011

Canal Walk: Botany Bay to Bridge 74A

One of the nice things about having my website about the Leeds and Liverpool Canal (and other canals) is the emails I get from people with their own interests. I have had emails from people interested in tunnels, water towersmilestones and World War Two defences. Today I got an email from someone with probably the most specific interest: Skew arch bridges. His interest was in Bridge 74A, a railway bridge between Adlington and Chorley on the former Lancaster Canal Southern Section, now the Leeds and Liverpool Canal. Along with a lot of interesting information about skew arch bridges there was a request for a photo of bridge 74A for the wikipedia page. Not a problem. 
Botany Bay
The lucky coincidence was that I was planning to visit some canal pubs today, one in Adlington and a couple by Chorley. While in the area I could walk the mile and a half to bridge 74A and take a few photos. 
milepost

We arrived at Botany Bay at lunchtime but after a big breakfast we weren't hungry so what better way to work up an appetite than a walk on the canal. We parked in the car park of the Lock & Quay pub, formerly the Railway. We crossed the bridge and walked down the steep cobbles to the towpath. The towpath mud was still frozen making walking a bit easier.

Not far along we came across a half mile post, 45.5 miles from Pall Mall in Liverpool. I couldn't remember seeing this one before so took a photo. 

There has been a lot of vegetation cleared and trees felled on this section so there was the chance to find lost mileposts. 

Tree

By Bridge 77, Workhouse Bridge, there were some brand new houses. They were not here last time we visited this section. Much nicer than the workhouse that gave the bridge its name.  We were passed by the worlds fastest Border Collie, zooming along the towpath at incredible speeds. 

Workhouse Bridge


We crossed the aqueduct near Bridge 76, and soon reached our destination at Bridge 74A. A skewed arch allows a railway to cross a canal at an oblique angle. And bridge 74A certainly does that. 
I took some photos, hoping to get whatever details a skew arch fan would appreciate.  
Bridge 74A

Under a Skew Arch
Next to the bridge was a little steam boat.

little boat

With the bridge well photographed we headed back. On the way back I took a slight detour to photo the aqueduct from below. Its hard to get a decent photo of an aqueduct when you are stood on top of it. 
Canal Aqueduct

There are still some impressive mills in Lancashire, but they are a dying breed heading for extinction. 
Crosse Hall Mill (Cotton)
On the subject of bridges, canal bridges are numbered eg 78. New bridges built between the numbered ones are given a letter eg 78A. If a bridge was built between 78 and 78A it would (I think) be 78AA. And if a bridge was built between 78 and 78AA it would be 78AAA. 
bridge 78aaa
We had almost got back to Botany Bay when I noticed a quarter mile post, almost completely buried. This one is 45.75 miles from Liverpool. So in helping one man's obsession I was rewarded with two examples of my own. We got back to the pub and started to review. 

1 comment:

MegaPedant said...

Hi Peter. I'm the skew arch bridge nut! I've only just discovered this page and want to thank you again for your generosity. I'm so glad you got something out of your visit to the canal as well. As far as I can tell, this bridge is unique. There may be one or two others built to the same logarithmic pattern (see the Wikipedia article for more information) but I believe they are all railway overbridges and can only be observed from the track. This one, I believe, is the only existing logarithmic skew railway underbridge (!) where the exquisite stonework can be viewed in safety. Given the fact that so few were built, this one might well be the only one of its kind that ever existed.

The photos are exactly what I wanted: the view square on to one of the faces, the view along the direction of the canal and the detail of the intrados, showing the curved stonework. Wonderful!

Thanks for the fascinating insight into the numbering system too. So bridges 74 and 75 would have been originals and 74A was "slotted in" between them at a later date (1838, in fact) when the railway was built.

John (a.k.a. MegaPedant on Wikipedia)