The river Thames in London is popular not only for its outstanding natural beauty but also for the historic structures located. Most of the structures in this river utilize hydraulic power for its usual operations and they work smoothly too. Because hydraulics makes the designed application more powerful, safe, and cost-effective. Also, with proper maintenance, these systems can function properly for a longer period. The 244 meters long Tower Bridge in London is one of the well-known hydraulic structure that connects Tower Hamlets with Southwark.
London’s Tower Bridge designed by John Wolfe Barry and Henry Marc Brunel was constructed in 1894 and is one of the famous landmarks in London, that will always attract visitors from every corner of the world. Other than the fantastic view, the engineering expertise of this bridge is also highly appreciated and popular. This bascule and suspension bridge on River Thames is at a height of 43m(pedestrian walkway). If considering the benefit of this bridge, it can permit both road transportation and water transportation, without any restrictions. We are going to learn more about the engineering excellence behind the operation of Tower Bridge in this article.
You might have seen the structure of Tower Bridge. The two towers with the majestic appearance and the liftable bridge are the key architectural features of this bridge. Each of these towers is 213-foot-tall and the distance between these towers is 200-feet. The 200-feet long bridge is split into two equal parts and both towers will carry the vertical reaction of the walkways. For permitting the transportation of large boats, the two parts of this bridge can be raised at an angle of 86 degrees.
Also Read: Thames Barrier Hydraulics
The hydraulic system and other operating machinery of Tower Bridge is located at the base of each tower houses. The force required for raising these two halves weighing more than 1000tons is provided by the hydraulic system by pressurizing the fluid. The bridge requires approximately 5-minutes to raise these walkways and road transportation will be blocked until the water passage is open. The water passage for small boats will be always open without any restrictions.
How does the hydraulic lifting mechanism in Tower Bridge works? When it was constructed in the 1800s, the lifting mechanism was powered by a steam-driven hydraulic system. This approach utilized three large boilers for creating the required power for working. Later in 1974, the new electro-hydraulic system was installed and it utilizes electric pumps for creating hydraulic energy for turning cogs and opening the bascules.
The hydraulic system powered by a steam engine utilizes pressurized water stored in six hydraulic accumulators for raising the bridge. The two 360-hp steam-engine will pump water at a maximum pressure of 750psi into the accumulators, each comprising of 20-inch ram. The current electro-hydraulic system uses a compatible oil rather than water as hydraulic fluid. The hydraulic motors and gearings will help to raise the bridge smoothly and safely using hydraulic power.