Project DescriptionDesigned together with Beckett Rankine, and dubbed “the most radical landing stage ever built in Britain” by the Independent, Millbank Pier is the fifth and last of the central London passenger piers to be built with funding assistance from the Millennium Commission. The pier enables a riverbus service to link Tate Britain at Millbank Pier to the London Eye and on to Tate Modern at Bankside Pier.
Traditionally, the appearance of Thames piers has been dominated by the dolphins which hold the pontoon in position. More recently, designs have used large monopoles but the visual impact, particularly at low tide, of either dolphins or monopoles can be overwhelming. The effect is worse on a single berth pier where the pontoon size is small in relation to the dolphin or monopole height.
There are two possible alternatives to dolphins for securing the pontoon. One option is to secure the pontoon is a recess built into the river wall. This was the solution used for the original piers on the Thames when the Victoria Embankment was constructed. Of the five original inset piers only one remains in its original state. This is the Police pier outside Somerset House.
To build a new inset pier would be prohibitively expensive unless it was done at the same time as reconstruction of the river wall, so this was not an option for Millbank.
The other alternative to dolphins is to secure the pontoon on radial arms. Radial arms are well established for securing piers with the most well know example being on Liverpool Landing Stage. On the Thames, Gravesend’s West Street Pier is secured laterally on a pair of radial arms and longitudinally by ground chains connected to anchors.
Radial arms are conventionally located entirely above water level with a landward fixing either to the shore or to a dolphin structure above MHWS. While there are many advantages of a shore fixing, the arrangement is rarely possible in Central London without major work to the Embankment wall. So, as an alternative at Millbank, shorter radial arms were secured at their inner ends to stub piles with the pile-radial arm bearing connection at mid-tide level. This arrangement provides a minimum visual impact.
The pontoon is held longitudinally by the brow which is at an angle of 35 degrees to the pontoon’s centreline and works as a third radial arm. The brow at 60 metres long is the second longest passenger brow on the Thames. This length of brow is necessary principally to maintain gradients below 1 in 12 for diable access. To achieve 1 in 12, with a 6 metre tidal range, required a deck ramp on the pontoon as well as a long brow. The deck ramp is aesthetically integrated into the pier.
Supporting a large brow on a small, and therefore lively, pontoon requires careful design of the brow’s bearings. This is particularly the case when the brow also serves as a radial arm. At Millbank the brow is supported upon three bearings. At the bankseat are two conventional pinned bearings, supported on a swivel beam. At its outer end the brow is connected to the pontoon by a single, central, spherical bearing. This arrangement allows the pontoon to roll and pitch without transferring any torsional loading to the brow.The design is highly original; both aesthetically and in its structural engineering. The engineering innovations helped to deliver the project to a tight budget, reduce maintenance costs, and enhance its appearance. The pontoon incorporates Angela Bulloch’s ‘Flash and Tidal’ artwork which has two elements, namely fluorescent lighting which changes colour in time with the tidal cycle, and 63 flashing lights on the external surface of the pontoon. The lighting performs a symphony of light over 150 hours.
Pontoon overall length: 39.5m
Length of berthing face: 30.0m
Pontoon width – maximum: 14.3m
Weight of pontoon without ballast: 230 tonnes
Weight of ballast – pig iron: 75 tonnes
Brow length between bearings: 60.3m
Brow width: 3.9m
Brow height: 3.5m
Brow weight: 88 tonnes
Radial arm length: 15.0m
Tidal range – springs: 6.2m