Visit to Thames Barrier and Tower Bridge on 14th June 2016
On the 14th June 6 intrepid members joined this trip in an event organised in conjunction with the retired members of the IET (Solent). Although only 6 RCEA members joined this party, for those of us who attended it was a most enjoyable day. Even Southern trains behaved themselves for us! On almost any other day we would have encountered delays. Because the trip required a rail journey from this area most started the day at around 0815 to get to Charlton at 1030. This then required a walk to the Barrier of about a mile. Coffee and snacks were available on arrival although, quite honestly, I’ve seen better. The visitor centre was closed to the general public for the day and open only to organised groups with each being given a 2 hour slot. This ensured dedicated access to the staff on duty and a very active question and answer session.
The visit started with a fully illustrated talk regarding its construction and operating history to date. We then descended to the lower floor of the visitors centre for videos made during construction and operating demonstrations using working models of the entire system. Disappointingly, heightened security didn’t allow us inside the barrier itself. Should that have been possible it would have taken the whole day.
Of great interest were the maintenance, backup and redundancy required to ensure the Barrier is always available. The options to make sure that power is always available are both comprehensive and expensive.For a full description it is much better to visit one of the numerous websites relating to the barrier. The following I found to be better than most : http://londonist.com/2015/01/secrets-of-the-thames-barrier
Here we see the Thames Barrier from the side. One could be forgiven for thinking that these huge structures had something to do with actually holding the water back. In actual fact it is cladding for the associated machinery necessary to operate each section of the barrier. Very impressive since this stainless steel cladding looks as good as new and has been in place in a hostile environment since construction some 35 years ago.
This picture shows a barrier in the closed position. Note the two access and maintenance tunnels built into the foundations on the river bed.
Each piece of the operating barrier was built in a northern shipyard and floated into place. It is difficult to imagine how considering that it weighs some 3200 tonnes! As one would expect nowadays you can find several videos of the operation on YouTube.
This picture shows the barrier in the maintenance position for cleaning. In this position it is completely out of the water so that all surfaces can be accessed.
This is a view as would be seen from a craft passing through the barrier. The barrier does not impose any more limits on the craft that can pass other than those that already existed for river traffic. The size of craft able to navigate the barrier is impressive and pictures can be found on the internet of an aircraft carrier that was put in place further up the river during the Olympic games.
The diagrams above show the three operational positions of the barrier. It is, on average, closed for flood protection 6 times a year. Weather patterns and tide predictions govern when it is necessary. Generally these occur during the spring tide in stormy weather when tidal surges occur along the east coast such as the disastrous event in the 60’s. On that occasion London was fortunate in so far as it was not as badly affected as the rest of the east coast.
Barrier closure takes place during low tide and uses the fact that the river water capacity, even in adverse conditions, can be controlled to be less than that which there would be from the tidal flow. In extreme winter conditions flood control can also be activated further up river at various locks (eg Teddington). The Barrier is reopened when the water levels on each side are level on the receding tide.
Quite clearly its use has to be seriously considered due to the fact that it closes the river to traffic for at least 6 hours in 12 during flood conditions.
Overall, its construction, planning and operation is quite fascinating and the above is a very brief description to whet your appetite for further investigation. It is well documented on the internet and it is to there I suggest one searches for further information.
Like all good visits the one to the Thames Barrier overran! This meant an almost athletic dash to reach Tower Bridge by the appointed time for our guided tour. It required a good walk to Charlton Station and from London Bridge terminal to Tower Bridge (North Side). Lunch was on “the hoof” wherever it could be obtained quickly. Not ideal, but to cram in two very well organised and detailed visits, necessary.
Our guide met us at the road level entrance to its visitor centre. We were then taken through an exhibition room dedicated to its planners, designers, builders and, of course being close to the city, financers! London in the late Victorian era was becoming extremely congested and at that time there was no crossing down river to alleviate it. This was largely because any conventional bridge at that time would have been a barrier to river traffic which was the lifeblood of the capital. So, it was within those constraints that Tower Bridge was conceived an innovative and
inspirational concept at that time.It opened in June 1894 and soon itself became congested. Where have we heard that before!
We then proceeded to the overhead walkways into which glass floors have been installed. Standing on them is a weird sensation – its a long way down to the water. The panoramic views across London from this height give an outstanding picture to the city on one side and up towards Parliament on the other. An excellent photographic opportunity.
Preceded by Followed by
Total length Height
Longest span Clearance below
Tower Bridge viewed from Shad Thames A100 Tower Bridge Road
– north side: Tower Hamlets – south side: Southwark
Bridge House Estates Grade I listed structure London Bridge
Queen Elizabeth II Bridge
Bascule bridge / Suspension Bridge 801 feet (244 m)
213 feet (65 m)
270 feet (82.3 m)
8.6 metres (28 ft) (closed) 42.5 metres (139 ft) (open) (mean high water spring tide)
30 June 1894; 122 years ago
After descriptions of various aspects from the guide we proceeded to the south tower for a descent to street level and on to the “engine room” to view the gear installed originally to operate bridge opening.
Quite clearly with an undertaking of this magnitude there are many varied tales and facts regarding its construction and operation. These are best described in Wikipedia at the following link: http://en.wikipedia.org/wiki/Tower_Bridge
On the south bank below street level you will find the engine room. State of the art in its day a magnificent restoration of the original steam engine, boilers and hydraulics can be viewed. Needless to say it is enormous and now replaced by a more modern electrically driven set of hydraulics. It is used to open the bridge on about 1000 times a year. Should you wish to see it in operation the times of opening are available on the internet for up to a week in advance so it is possible to plan a visit to coincide.
This shows a view from the walkway of Tower Bridge.
This is a view through the glass floor – not for the faint-hearted!
The picture above shows one of Original Boilers
The picture above shows the original steam engine hydraulic pump 13
The previous pictures were taken on the day and represents only a small selection of that to be seen. The guided tour was so good and excellently presented by the appointed guide that it was deemed appropriate to offer a tip – yes a tip! Virtually unprecedented for a service that had been prepaid.
Overall the day was a great success and personally I would like to see more trips like this but, of course, we do need sufficient interest amongst our membership.