The brickwork looks to be in good condition, though the retaining wall on the approach needs attention. Beyond the bridge will be the cutting for the HS2 line.

There are quite a few nice old railway bridges in North Bucks, but it looks like the Highways Agency want to demolish this one, though it was in quite good condition when I visited it this week.

This bridge is nearly 125 years old, a part of our railway heritage and a local landmark on a footpath near Twyford Mill.

When HS2 is completed it will be about 120 feet from the edge of the cutting. The existing farm track will be carried over the cutting on a new bridge.

From the Government’s plans and what a local dog walker told me, this original bridge will be demolished; instead there will just be a ramp up to the new one. I believe there's enough room to keep this bridge and make it part of the ramp to the new one.

I see there’s another bridge that will be lost, too, about a quarter of a mile to the South East. But I didn’t realise until I came home again.

The Monday Photo

There’s a good chance at least one of the Christmas cards you’ve had this year had a mail coach on it.

The coaches are almost always red, there’s a chap on the back blowing a horn, and the snow lays round about, deep and crisp and even.

These coaches relied on the turnpike roads to reach their destinations, because they knew they’d be maintained with the money turnpikes took from tolls. The bridge took the 1722 Wendover and Buckingham Turnpike across Shipton Brook, just down the hill from the hamlet of the same name, next to Winslow.

Here’s another view of Shipton Bridge in slightly warmer weather, and here’s one more, of the 18th Century arched bridge from the middle of the brook in mid summer.

I can just imagine four horses pulling a red coach over this bridge in the depths of winter. The horn is blowing. Everyone on the top of the coach has bundled up against the intense cold. The snow is at least a foot deep and there are no other wheel tracks.

This will be the last Monday Photo of 2021; I’ll be taking a couple of weeks off over Christmas and the first week of the new year, returning on Monday 10th January. But there’s one more Thursday post to go this year, on the 23rd of December. See you then.

The towpath hangs out over the edge of the aqueduct.

The Iron Trunk, the aqueduct that carries the Grand Union Canal 40 feet above the Great Ouse, is the third one to be built here.

The first one collapsed, the second one was temporary, and the one we have now is 210 years old. The canal company changed the course of the river and the shape of Buckinghamshire to build it.

Here’s the timeline.

The Iron Trunk aqueduct.

Canals take a wriggly path, following the contours of the land as much as possible.

But sometimes that’s not practical, as the engineers of the Grand Junction Canal realised when they came to the Ouse Valley.

A one mile embankment carries the canal across the valley, with a cast iron aqueduct over the Great Ouse. The aqueduct is known locally as the Iron Trunk.

The Aqueduct is a great piece of engineering. It’s about half a mile from the road and the nearest parking spot, but well worth a visit. It’s a nice walk, too.

The Monday Photo

Only three of the bridges that Walker and Co. of Rotherham made are left in the world, and Tickford Bridge in Newport Pagnell is one of them.

Built in 1810,  it's also the oldest cast iron bridge in the world that carries modern traffic.

The other two existing bridges made by the company are older. The earliest one was built in 1801 in Spanish Town, Jamaica, and was the first cast iron bridge to be built in the Caribbean.

The other cast iron bridge was erected in 1802 on the estate of Stratfield Saye House in Hampshire, not far from Reading.

Walker and Co. also made cannon for the navy. It’s thought that around a quarter of all the cannon in Nelson’s fleet at the battle of Trafalgar were made by the company, and 79 out of the 105 cannon on the Victory bore the Rotherham firm’s WCo mark; they were an expert casting firm.

The Newport Pagnell bridge was cast in sections. It was taken by sea to London, then by boat along the Grand Junction canal, which had only opened five years earlier. It wasn’t too far by road from the canal to the site of the new bridge.

The old bridge over the Ouzel there had to be replaced as it had become “ancient and decayed”.

The new bridge had been designed with six arched trusses set side by side, linked together by plates. Each one is made of eleven separate vouissors (which work like the wedge shaped stones that form a masonry arch) joined together with mortise and tenon joints, held tight by wrought iron wedges.

The arches are under compression; they have to be as cast iron, like stone, is strong in compression but weak under tension. The railings and central lamp standards are also cast iron, and the bridge abutments are of local sandstone.

The bridge needed little work or alterations for ninety years, then in 1900 wrought iron plates were added to the two centre bays when one of the deck plates fractured.

In 1972 the stone abutments received extensive repairs. Four years later a reinforced concrete deck on plastic foam had to be laid over the bridge to evenly spread the load of modern traffic, but in 1999 the bridge had to be strengthened again with carbon fibre. This all works, as you can see by the bus.

In the mid 1990s bollards were installed on the bridge, creating a width restriction to stop lorries and other large vehicles. It wasn’t popular; the gap was too narrow and quite a few cars lost mirrors on the bollards.

I wonder now if the restrictions were there to protect the bridge until it could be strengthened again. If you know anything about all this, please comment below.

Tickford bridge is a very fine example of early civil engineering in cast iron, which is why it is Grade 1 listed.

Not far from Goosey Bridge at Olney (all the shots this week have something to do with bridges), my sister in law leads the way across a field by the river. The sheep are used to walkers and almost completely ignored us.

The Distance Project 23

Even for people like me who are a bit insular, there’s a need for human contact with friends or family.

Talking on the phone or on some sort of video link is all very well, but it just isn’t the same as meeting face to face, even if we have to keep our distance. Recently under lockdown, this means I’ve been out walking…