Author Archives: Kieran Mclean

With the acquired information, we set out designing a bridge footprint that would tick all the necessary boxes.

Our initial design was an L-shaped bridge, connecting Mithras Car Park, Preston Barracks and Watts Car Park. While this proposal met all requirements set by the brief and regulations, we concluded that it could be more inclusive to the general public by simply providing a method of crossing the road rather than only landing on university sites.

We then revised the design and added a branch which lands directly onto the Lewes Road walkway to encourage public use:

The next step was to make note of all the parameters of our given site.

We firstly researched the required dimensions, starting with the width needed on the decking to accommodate all users. The Department for Transport suggest a minimum width of 3 metres for a two-way cycle path, and 2 metres for a pedestrian path with the view to accommodating wheelchair users, as laid out in Local Transport Note 1/12 (page 40).

Secondly, we looked at the height needed to successfully clear all vehicular traffic. The tallest vehicle which uses Lewes Road is the double-decker bus, which stands at approx. 4.3 metres tall. However, the Highways Agency requires a headroom of 5.7 metres for footbridges. Part 2.8 of Approved Document K states that ramps should have a maximum gradient of 1:12, meaning the subsequent ramp must be at least 68.4 metres.

Next, we had a look at external influences, the main one being the tree obstructions. In an attempt to find out if any of the trees in question were protected, we searched the Brighton & Hove Council website for Tree Preservation Orders. Unfortunately, the council charge over £30 to release the documents, so we were unable to acquire the necessary information.

A key consideration,as briefly mentioned on the opening day, is the redevelopment of Preston Barracks. As this is due to form an addition part of the University of Brighton’s Mouslecoomb campus, it is highly likely that the client is hoping to use the new footbridge to integrate this land with the existing university buildings. Our research (eventually) led us to the official website for the redevelopment, Momentum for Lewes Road (www.momentumlewesroad.com). Here we found the ‘Masterplan’, the proposed layout of the renovated area:

The new buildings situated in what is currently Mithras Car park meant that we were not able to stretch the bridge from the steps immediately outside of Mithras House, which would have cleared the road height by around 7 metres. Instead, we would have to use some land much nearer to, if not part of, the existing pathway. Another observation we made is that the renovators plan on removing some trees in order to install a footbridge of their own, which implies that we wouldn’t have a problem removing any obstructing trees for our bridge.

Resources:

DMRB Volume 6 Section 1 Part 2 – TD 27/05 – Cross Sections and Headrooms: http://www.standardsforhighways.co.uk/ha/standards/dmrb/vol6/section1/td2705.pdf

Momentum Lewes Road Masterplan: http://www.momentumlewesroad.com/plans/masterplan-2/

Tree Preservation Orders (Brighton and Hove City Council): http://www.brighton-hove.gov.uk/content/leisure-and-libraries/parks-and-green-spaces/tree-preservation-orders

Building Regulations 2010: Approved Document K: Protection from falling, collision and impact

1. Ponte Segunda Circular

Location: Lisbon, Portugal

Designers: Maximina Almeida & Telmo Cruz

As referenced in the title, this steel structure crosses the Second Circular Road in Lisbon, and is accessible by cyclists and pedestrians. This bridge is held up by two columns either side of the road, and is therefore void of structural support on the road itself, which is beneficial as the road would not have had to be fully closed for construction, nor would it be for maintenance. There are 5 methods of access, 4 ramps and 1 set of stairs. Although the bridge has an inclusive design, it is unfortunate that it couldn’t be entirely step free. It is possible that the steps were installed by choice as there are enough wheelchair access routes, and a quicker route by foot was desired.

The parapets are below shoulder height, leaving cyclists somewhat vulnerable to falling over the side in the event of a collision.I am particularly drawn to this bridge due to its network of connections, which utilise the land footprint to provide multiple potential routes for users, depending on their destination. This consideration would be appropriate for the given brief as university students often have to travel between the buildings, and destinations can vary both student to student and day to day.

Jan Waaijer Bridge

Location: Westerpark, Netherlands

Syb van Breda & Co. Architects

The primary element of this bridge which sticks out is the segregated, differentiated paving for cyclists and pedestrians. The different pavings provide subtle instruction for users, removing the need for aesthetically hindering barriers.

Like the previous, this bridge also accommodates the need to access more than two destinations, and allows users to peel off in their desired directions seamlessly.

The lampposts, which also act as structural members, have drawn their form from the surrounding forestry, an effective method of townscaping.

Melkwegbridge

Location: Purmerend, Netherlands

NEXT Architects and Rietveld Landscape

This bridge offers an alternate solution to giving pedestrians and cyclists designated spaces; cyclists (and wheelchair users) are provided with a flat zig-zagged deck while pedestrians walk over a steep, arched upper level.

The week started with an introduction to the brief: to design a pedestrian and cyclist footbridge to link both parts of the University of Brighton’s Moulsecoomb campus, as well as Preston Barracks which is to be redeveloped and integrated to the campus.

This was followed by a lecture introducing us to the fundamentals of bridges: bridge components, different construction methods and existing footbridges around the world.

Next, we visited the site to gain a first-person perspective of the task at hand. The planes on which Preston Barracks, Watts Building and Cockcroft Building are found are less than a metre above the level of Lewes Road, while Mithras House is located on a steep incline, and is subsequently around 7 metres above Lewes Road.

View of Mithras House from Lewes Road

There are also many trees lining the Lewes Road pathway (Mithras Road side), as well as just within the limits of Preston Barracks, blocking a direct route between the two. These could pose a problem if permission can not be given to remove them, and if they were to be removed, it may be necessary to devise a way to replace their environmental benefits.

Cluster of trees along Lewes Road

At the front of Watts, there is an area of cycle stands and an enclosed bike shed adjacent to it. It was around midday and less than half of the cycle stands were in use which implies it is not heavily used. For this reason, I thought it may be an ideal platform to use for the bridge to take off from. The bike shed is currently gated off due to construction works, and is therefore not in use. Once it becomes available again, it would replace any bike spaces lost.

Bike shed, currently not in use in front of Watts Building

Cycle stands in front of Watts Building