Thames taxis

A bald-headed man wearing a fine-knit pullover has settled down on one of the back seats. He has a bottle of Peroni beer in one hand, and his other arm around his wife's shoulders. Standing near them is a young Asian woman in a pink cap. She is filming the Tower of London on her smartphone – an ancient fortress on the left bank of the river that for centuries was the seat of the English monarchs. Today, its solid stone walls protect the crown jewels. "Everyone uses our service – tourists, commuters and Londoners," says Sean Collins. His company's catamarans have been plying their trade on the Thames for 15 years. In the summer months especially, they are full of tourists. "A lot of passengers use our boats as taxis to get to the sights along the Thames," he recounts. The young Asian woman now turns her attention to the right bank where she has spotted London City Hall, a modern, egg-shaped, glass edifice. Shortly afterwards, the Monsoon sails under Tower Bridge and the rest of the passengers reach for their mobiles to take souvenir snaps as well. After all, the venerable lifting bridge is a London landmark, much like the Eiffel Tower in Paris.

"The reman engines were the perfect solution"

After passing under the bridge, the river bus increases speed perceptibly. The brown water of the Thames is whipped up into a white foam at both ends of the catamaran. The Monsoon and her five sister ships measure 38 m in length, offer space for 220 passengers, and have been in service on the Thames since 2008. They are each powered by twin mtu engines – originally brand new, now replaced by what are called 'reman' units. These are mtu engines that have been fully remanufactured for a second service life after 12,000 hours of duty. "mtu's reman principle is the perfect solution for us," says Sean Collins. "mtu supplies us with a reman engine, we remove the old one and install the as-new one. The old one goes back to mtu for reconditioning," he continues. If they had opted for the conventional complete overhaul, the clippers would have stood idle for a good couple of weeks, because they all entered service at the same time. Another advantage of reman engines is that they are cheaper than brand new ones. "Our technicians swapped over the old engines with the new reman replacements inside a day," relates Sean Collins enthusiastically. So the operators were able to keep the catamaran downtimes to the absolute minimum. To date, the Thames Clippers company has bought over 20 reman engines, and some of the river craft are already running on their second reman unit.

Next stop: North Greenwich

While Sean Collins is talking about reman engines, the O2 Arena comes into view on the riverside. The rear seats in the boat are now occupied by a dozen or so schoolboys from Devon in their blazers and caps. Their teacher points towards the O2 Arena and explains to the children what they can see. The world's largest dome structure, 365 m in diameter and 52 m high, was opened in 1999 to celebrate the millennium and now serves as a sports arena and concert venue. The enormous edifice also gained fame in the James Bond film "The World Is Not Enough", which ends with a high-speed motorboat chase right in front of the O2 Arena. The clipper ties up at North Greenwich Pier not far from the O2 Arena. This is the terminus for route RB1, and the crew uses the turnaround time to replenish water supplies and clean the boat up a little before new passengers come on board.

After about 20 minutes, the Monsoon sets off again in the direction of the London Eye at the other end of the route. The boat accelerates so quickly that the passengers willingly sit down in the stern seats. With a power output of 900 kW, the engines can propel the catamaran at speeds up to 29 knots (54 km/h). The greatest load on them comes from constant acceleration and deceleration between stops. "That is why it is so important to thoroughly check the engines every morning and evening," explains Sean Collins. Minor servicing jobs such as oil changes or filter replacement are carried out by Thames Clippers' own technicians. For major maintenance assignments, the company has taken out a contract with mtu's British subsidiary, MTU UK. The maintenance agreement covers the replacement of fuel injectors, turbochargers and fuel pumps when the engine has reached half of its service life. During their first twelve months of service, the engines are also checked regularly by mtu service technicians.

mtu-powered High Speed Trains (HST)

"Which stop is nearest to Paddington Station?" asks an elderly man with gold-framed glasses, in a checked shirt and shorts. "The best place to get off is Embankment Pier," answers a crew member on his way to the bridge command center. There is a direct underground connection from there to the mainline station made world-famous by Agatha Christie in her thriller '4:50 from Paddington'. Platforms one to five are the terminus points for Great Western Railway services to and from the southwest of England. Great Western Railway closed a service contract with mtu in 2007 for its Class 43 trains. Capable of speeds up to 200 km/h, these have been repowered with Series 4000 reman engines, each delivering 1,680 kW. The fleet totals 119 high-speed trains (HSTs) equipped with diesel-electric traction, and some of these often complete a return trip from London to Penzance at the southernmost tip of the country in just one day. Courtesy of their mtu Series 4000 engines, the HSTs boast 99% availability and are in service for up to 17 hours a day.

High season for Thames Clippers

After a couple of passengers have disembarked at Bankside Pier and others have boarded, the catamaran casts off again. Bankside Pier is the penultimate stop on route RB1, reached after a journey time of 45 minutes. This main route carries 1.6 million passengers a year, while the combined total for all Thames Clippers services is 3.5 million people a year. "We have the highest passenger numbers in the summer, and whenever there is a strike on the Jubilee Line underground service, we are packed out," says Sean Collins, who goes on to explain that the number of tourists among passengers has increased substantially in recent years. When the Olympic Games took place in London in 2012, the Thames Clippers catamarans had even more passengers than usual. That was also a big test for mtu Service. "MTU UK had the foresight to send us important spare parts and a reman engine in reserve in case of an emergency," Sean Collins recounts. When a problem did actually crop up with one of the engines in the middle of that busy period, the Thames Clippers technicians were able to remove it and install the reman replacement within a day. Later on, they found out that it had simply been a worn part that had caused engine failure.

When the Monsoon ties up at the London Eye stop next to the gigantic ferris wheel, the trip is nearly over. The last highlight of the journey for tourists is the view of the Houses of Parliament and the world-famous Big Ben clock. For Sean Collins, the sight of the clock tower has become routine, but the excited passengers are eager to take a few more snaps before the boat reaches its final destination at Embankment. For the crew, meanwhile, there is just a short break before the river bus sets off again on its trip to London's tourist attractions along the Thames.