Yorkshire Bridges: 31. Newlay Bridge, Leeds

Okay, this is the penultimate structure in my current sequence of posts. For this one, I headed west out of Leeds to Horsforth, to discover a real gem of a bridge.

Spanning the River Aire, Newlay Bridge was built in 1819, and is one of the oldest surviving cast iron bridges in Yorkshire. It was built by the Bradford-based iron foundry Aydon and Elwell, who also built bridges which survive at Sowerby Bridge (1816) and Walton Hall (1828). Cast iron bridges in Yorkshire date back, of course, to one of the first iron bridges in the world, built at Kirklees in 1769 (yes, ten years before that other one).

The bridge was originally constructed for £1500 at the request of landowner John Pollard, replacing a previous structure built in 1783. A halfpenny toll was charged, earning Pollard £600 per year.

Different accounts vary on what happened to the bridge in later years: Civil Engineering Heritage reports that the bridge was taken over by the Midland Railway and Horsforth Council in 1880, providing access to Newlay and Horsforth Railway Station. The Newlay Conservation Society mention that the Midland Railway built a new footbridge in 1886, which would seem odd if they had just acquired this bridge. Photos suggest the second bridge to have been just downstream, closer to the river weir.

The Pastscape website has a hugely detailed description of the bridge, so I'll not repeat that here. The bridge comprises four cast iron ribs, separated by cast iron bracing members. It spans approximately 25m.

The structure is very well apportioned. The layout and spacing of the bridge spandrel members is surprisingly modern. The edges of the main ribs, and also the centreline of the spandrel members are reinforced with small outstands, which also provide a degree of visual definition to what would otherwise be quite plain.

The stringcourse fascia is subdivided into repeating panels, with the smaller panels coinciding with the main parapet posts above. These posts are an ornate ironwork design, with plain vertical infill bars in the sections in between. Panels on the parapet credit Pollard, Aydon and Elwell.

Leeds Council are planning to refurbish the bridge in summer 2018, although I thought it looked in pretty good condition already. The parapets were repainted as recently as February 2017, although the underside of the bridge was not repainted at that time. As at Leeds Bridge, the bridge will be repainted using a High Ratio Co-Polymerised Calcium Sulfonate Alkyd paint system, specially sourced from North America. The driver seems to be the bridge's bicentennial anniversary, which falls in Spring 2019.

This is a well-preserved, interesting and historic bridge, in a very attractive setting, and well worth a visit if you are in the area.

Further information:

• Google maps
• British Listed Buildings
• Pastscape
• Newlay Conservation Society
• Civil Engineering Heritage: Northern England (Rennison, 1996)
• An Encyclopaedia of Britain's Bridges (McFetrich, 2010)

Yorkshire Bridges: 30. Riverside Way Bridge, Leeds

This footbridge was opened in 2007, to a design by Capita Symonds and Carey Jones Architects. Also known as the Whitehall Bridge, it cost £1m to build.

It's a classic modern tilted-arch design. I'm not sure who first designed one of these, but it's a typology that has definitely caught on. I've designed one myself.

Structurally it's fairly straightforward. The bridge deck is curved in plan, so tends to tilt away from its supports. The arch is also curved in plan, so tilts the other way. Connecting the two with cables allows the weight of the arch to balance the weight of the deck and any pedestrians. In addition, the stiffness of the deck helps to brace the arch against buckling.

Riverside Way Bridge is mildly decrepit, with substantial grime disfiguring the metalwork, and one of the parapet cables having snapped and come loose. This could have been guarded against by using shorter lengths of cables, rather than wires which run the full bridge length.

I think the arch looks pretty good from most angles, and I like the detailing where the parapets intersect the arch rib.

Further information:

• Google maps

Yorkshire Bridges: 29. Granary Wharf Footbridge, Leeds

Now, it's time for a modern classic.

I've called this bridge Granary Wharf Footbridge, due to its proximity to Granary Wharf in Leeds, but it could just as easily be called Waterman's Bridge, as it carries Waterman's Place across the River Aire just next to Leeds Railway Station.

In discussion with another bridge designer about bad bridge design, my collocutor considered this to be an essentially honest bridge - clear in how it works and what it does. It is a cable stayed footbridge, with cables on one side of the support tower only, and the tower is therefore immensely stiff and robust, so as to resist the one-sided loading.

It can be seen that the weathering steel support tower is immediately adjacent to a building, and so it could be argued that the designer had little choice, unless they wanted the bridge to rely on the building for support.

I can see the honesty, but this is nonetheless an execrable bridge design. The cables, and the tower are unnecessary: the span is 34m, and several alternative structural forms would have been suitable. The detailing is well done, but the concept is shamelessly crude.

The culprits? I don't know if an architect was involved, but the engineer was Ramboll, and the bridge was fabricated by SH Structures.

Further information:

• Google maps

Yorkshire Bridges: 28. Victoria Bridge, Leeds

Continuing west on the River Aire, the next bridge is Victoria Bridge, completed in 1839 by either George Leather (if you believe this Grade II Listed Building's listing) or his son John Wignall Leather (if you believe the younger Leather's obituary). The Leathers were also responsible for Crown Point Bridge in Leeds, as well as the Stanley Ferry Aqueduct.

Today the bridge carries Victoria Road / Neville Street, a busy highway that carries traffic below Leeds Railway Station.

Victoria Bridge is an elliptical masonry arch bridge, with what I would call "sunrise" voussoirs i.e. it's facing stonework is arranged in a radial pattern. It is an attractive bridge, nicely detailed, although the mutules are a bit fussy (every time I read the Listing for one of these masonry bridges, I seem to learn a new word).

The stringcourse on the bridge shows clear signs of sagging, presumably long-standing.

Further information:

• Google maps
• British Listed Buildings
• CanalPlanAC

Yorkshire Bridges: 27. Leeds Bridge, Leeds

This is another of the older bridges spanning the River Aire in Leeds, but far from the oldest. I previously reported on Crown Point Bridge, complete in 1842, and will shortly cover Victoria Bridge, completed in 1839. The Leeds Bridge which can be seen today wasn't opened until 1873.

However, a bridge at this site may date back at least to the 14th century. The medieval bridge was widened several times, in 1730, 1760 and 1796, before the present-day bridge was built to replace it.

The bridge visible today is a cast iron arch. A plaque on the bridge credits numerous mayors, aldermen and councillors, as well as William Henry Barlow, Consulting Engineer, and Thomas Dyne Steel, Engineer. The contractor was David Nichols, while the ironwork was provided by John Butler.

Barlow also designed the Clifton Suspension Bridge (with John Hawkshaw, completing Brunel's design), and St Pancras Station. Steel had begun his career apprenticed to James Rendel, and had wide experience in railways, mining, and industrial manufacture. According to his obituary, he became a specialist in iron roofs and bridges later in his career.

The bridge is Listed Grade II, and according to the listing, only the external arches are cast iron, with the internal arch ribs being in wrought iron and the deck in steel.

The bridge is currently undergoing strengthening and refurbishment, with a new reinforced concrete slab being installed before complete repainting takes place. The paintwork will be undertaken using a High Ratio Co-Polymerised Calcium Sulfonate Alkyd paint system, specially sourced from North America.

Further information:

• Google maps
• Wikipedia
• Structurae
• British Listed Buildings
• CanalPlanAC

Yorkshire Bridges: 25. Centenary Footbridge, Leeds

Completed in 1992, the Centenary Bridge was claimed to be the first new crossing of the River Aire in Leeds for over 100 years.

It was planned and promoted by the Leeds Development Corporation, and engineered by Ove Arup and Partners. The contractor was Kier, with Billington Structures fabricating the steel elements and C.V. Buchan precasting the concrete.

The site was (and is) asymmetrical, with a relatively narrow approach on the north bank of the river, and a wider open space on the south. The resulting design is an asymmetrical cable-stayed footbridge.

The A-frame mast is 18.3m tall, with two reinforced concrete legs supported at their base on bearings. The bridge deck has an 11.8m backspan and 43.3m main span, and is a steel half-through girder bridge, with Vierendeel edge girders formed from closed hollow sections.

A short article in the Arup Journal describes the bridge but doesn't explain its articulation. For an asymmetrical cable-stayed bridge of this type, there is an out-of-balance thrust in the bridge deck, acting towards the mast from the main span. This can be accommodated at the mast, but in this instance appears to be resisted at the back-span abutment, where the horizontal component of force in the deck is balanced by the force in the back-stays. Net vertical forces must be carried by the foundations.

The bridge will expand and contract under temperature from the fixed support at the abutments, which is presumably why the concrete mast has bearings at its base. The mast was precast, so a simple support detail at the base may also have been desirable for that reason.

The bridge girders are not very good looking, and doubly so due to the accumulation of dirt on these and other parts of the bridge.

The parapets use horizontal stainless steel wires, and are an attempt to lighten the general appearance of the bridge.

As with many urban bridges, there were a number of "love locks" attached to the parapet when I visited, although the local council clearly does not want them on the bridge.

This is not, in my view, a great bridge design. It's easy to see why the designers put the tall mast in the open space on the south bank, but the mast and associated steps and ramps for this end of the bridge dominate this space so that much of the openness has been lost.

The tower is angled at a very slight angle away from the river, and I think a vertical tower would have looked better in this close proximity to surrounding buildings.

Further information:

• Google maps
• River Aire Footbridge (Arup Journal, 1993)
• Structurae
• CanalPlanAC

Yorkshire Bridges: 24. Crown Point Bridge, Leeds

This is the next bridge across the River Aire in Leeds, proceeding west from Knight's Way Footbridge.

Crown Point Bridge was built in 1842, and is Listed Grade II. The Listing states that it was designed by George Leather, but an ICE obituary attributes the bridge to George's son, John Wignall Leather. The pair played a key part in development in the Leeds area at the time, developing the Aire and Calder Navigation, and a series of bridges, including Monk Bridge (1827), Victoria Bridge (1839) and the Stanley Ferry Aqueduct (1839).

The Crown Point Bridge was constructed to provide a connection to new areas of Leeds then undergoing development, and was authorised by an Act of Parliament in 1840. In its original form, it comprised ten parallel cast iron arch ribs, spanning 120 feet.

The cast iron elements were supplied by Booth and Co., of Sheffield's Park Ironworks, at a cost of £8,750. The total bridge construction cost was £36,000, including approach spans. Initially the bridge was tolled, although the toll was removed in 1868.

The bridge is ornate in the extreme, but it remains elegant due to the basic clarity of the different pieces - the arch ribs, spandrel X-bracing, beams and parapets.

In 1989, the bridge was assessed as unsuitable for heavy modern traffic, and Leeds City Council designed a strengthening and widening scheme, completed in 1995. The basics of the scheme can be seen from below the bridge: the two edge arch ribs on each edge of the bridge have been retained and relocated, and twelve new steel arches have been inserted in between.

The cost of the scheme was approximately £2.2m. The existing foundations were widened and strengthened with the insertion of new mini-piles. The arch ribs on the eastern face were extended in length by replacing one 7.5m segment with new longer cast iron segments: this is visible in some of the photographs, although it's certainly not immediately obvious.

The bridge alterations won a City of Leeds Award for Architecture (1996) and were Commended in the ICE Yorkshire Association Awards (1997). Photographs taken during construction can be found at the Richard's Bridges website link below, the Richard in question being J Richard Kay, former Chief Bridge Engineer for Leeds City Council.

Further information:

• Google maps
• Richard's Bridges
• Structurae
• British Listed Buildings
• CanalPlanAC

Yorkshire Bridges: 23. Knight's Way Footbridge, Leeds

From Leeds Dock, I returned to the River Aire, heading west.

Knight's Way Footbridge was built as part of the Clarence Dock redevelopment in 2007, and is a two span bridge across the River Aire, designed by Buro Happold.

It belongs to a family of crane-like cable-stayed bridges, with other examples in the UK including Lockmeadow Footbridge (1999), Lune Millennium Bridge (2001), Newport City Footbridge (2006), and the Eureka Skyway (2011).

The bridge deck is partially supported by the cables, which carry the forces up to the tip of each pylon, where they are balanced by the compression in the pylon and tension in the overhead cables. The effect is that most of the load on the bridge, including its self-weight, is carried to the foundation on the central island in the river.

The whole bridge will have a tendency to tip over when only one of the two spans is loaded. One way to resist this effect would be to have cables running to ground anchorages at one or both ends of the bridge (the solution adopted for the Newport City Footbridge).

The other, used here, is for the out-of-balance overturning to be resisted by the bearings at the two ends of the bridge, implying that these are probably uplift-resisting bearings. This places a higher bending demand on the deck, losing much of the efficiency that a cable stayed bridge design would normally have.

As with many white-painted bridges, this one is affected by a considerably build-up of grime. Cleaning bridges is rarely a high priority. I have no idea whether this bridge is the responsibility of the city council or the developer, but it often seems to be the case that "landmark" bridges built as part of an exciting new development prove to be a maintenance burden, if their maintenance is remembered at all.

The bridge deck has upstand girders on either side, which I would expect to spoil the appearance of what should be a lightweight, transparent form of structure. The floor plate is about half-way up the girders, and I guess a series of crossbeams are hidden below. The alternative solution, a box girder below floor level, would have given a more slender appearance, but would have been more expensive.

The depth of the girders is not out of proportion to the bridge span (especially given the bending required to prevent overturning of the masts), but seen while standing on the bridge, this arrangement gives the parapets a tacked-on appearance, rather than integrated.

Further information:

• Google maps
• Structurae
• CanalPlanAC