Wednesday, 5 May 2010

Marple Aqueduct

Marple Aqueduct
April 12th 2010
Easter 2010 part 17

The Marple aqueduct is as frustrating as it is impressive.

One of Marple Aqueduct's great stone piers

Impressive because it is probably the greatest of the stone aqueducts ever built, but frustrating because it is nigh on impossible to get a side on perspective due to the dense tree canopy which fills the narrow Goyt valley.

Marple Aqueduct - side profile

Given the significance of this structure I have taken the liberty of lifting the explanatory content from my aqueducts blog:

A 105 yard masonry aqueduct, constructed by Benjamin Outram between 1794 and 1800 carrying the Peak Forest Canal 90 feet over the River Goyt on three graceful arches.

The structure is innovative in a number of ways, with its oval base piers being made of red sandstone sourced from the nearby Hyde Bank Quarry, and the upper sections using white masonry. The upper sections borrowed a construction technique from William Edwards in the shape of spandrills (drills through the spans!) piercing the haunches of the arches, reducing the weight of masonry.

The end result is a hugely elegant structure fully justifying its status as an Ancient Monument.
As at Chirk, a later railway viaduct runs parallel all but slightly higher than the canal aqueduct, detracting from its grandeur but even so, it has rightly been described as one of the finest monuments to the canal age.

We had moored between the Marple Aqueduct and the bottom of the Marple Flight of locks and having woken early I thought a closer inspection of this amazing aqueduct was called for. A footpath descends the 90 feet from towpath at the northern end, and as I went down my mobile rang - first it was Dr D calling to wish me a happy birthday, then Belle and finally the Bag Lady all in the space of 10 minutes. The funny thing was that until that point I had completely forgotten it was my birthday, and it certianly wasn't on Jeffs mind when he has blearily acknowledged my departure at 8.00am.

Central span, with the repair job very visible

I have never seen a contemporary photo of the complete Marple Aqueduct and the only one to hand seems to date from soon after it's construction. Photographing it's three soaring arches is therefore a bit of a challenge and the best I could do was to capture some images of various facets, hopefully illustrating the scale and grandeur via a mosaic.


When you get close up you can see that all is not well with the aqueduct. In fact the whole thing seems to be held together with tie rods and anchors, some passing through the spandrills, some passing under the arches and others drilled through the canal bed. 

Aqueduct with Viaduct behind

Whilst this all holds the white stone top section in one piece, the ironstone support pillars are also showing signs of their age, weathering away and almost crumbling before our eyes. I am not saying it's on life support just yet, but it has certainly enjoyed more reconstructive surgery than Dolly Parton in it's attempts to save of the negative impacts of time.

Towpath view

A scrambled around the piers for an hour or so, testing out ever more absurd vantage points but wherever I went there was a tree in the way. I have done my best!

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