Getting reliable signal on your phone isn't easy when you're travelling at 125mph. That's exactly why we've had to inject some amazing technology to a fleet of 27 East Midlands Trains. Read on to find out how...

train inside

If you’ve been following Vodafone Social over the past few months, then by now you know how we’ve pushed mobile phone reception up into the peak of London’s tallest building. But what if you tipped the Shard onto its side, and then fired it down a track at 125mph? That’s the challenge facing our network team when it comes to bringing you reliable coverage from your train seat.


TheshardSignals in the Shard
Uncover the hidden work that ensures you can tweet your pics of the view from the 72nd floor of the Shard.


Never fear, though: there is a solution. We have the technology. We’ve been to the home of East Midlands Trains in Derby to find out exactly how Vodafone’s been injecting mobile reception into your high-speed commute.

Derby, we have a problem…

“The mobile reception on the Meridians was poor,” says East Midlands Engineering’s Paul Caffrey, “and it was partly due to the design of the trains.” If, like us, you’re a little rusty on your train makes and models, the ‘Meridians’ Paul’s referring to are the Meridian 222 fleet – the 27 trains that run between London and Sheffield on a daily basis. And Paul’s taken us backstage on one of the 222s to explain what the problem was.

“It’s a modern train, but its materials – specifically a metallic coating that’s designed to shield the windows from bright sunlight – aren’t conducive to good mobile phone signal. Because of that, talks were held in 2012 to see what could be done to improve the mobile phone reception on the train.” Those talks were with us at Vodafone and our engineering partners. We were keen to get a solution in place because we know how frustrating it can be to lose a call or be unable to check your social feeds on the move. Luckily, between us and Paul’s team, we had an answer…

Antennas, boxes and wires (Oh my!)

train yard main

“During our initial meetings, we’d see replicas of the equipment we needed to include, and we’d go onto the trains and see where we could make it fit,” says Paul.

“The first hurdle was the fact that this was a retrospective upgrade, so we had to find a home for new equipment that wasn’t considered in the initial design of the train, and that also required power and ventilation. Eventually we figured it out: we identified a cupboard next door to the onboard customer shop which was being used to keep sugar, coffee, tea, etc, so we moved all of that stuff elsewhere and put the booster box in there.”

booster box

That transmitter is the lynchpin of the system now in place on all 27 trains, but it’s not the only piece of kit needed. “We also had to provide RF cabling that’d run all the way from one end of the train to the other,” says Paul. “That meant running cables all through the roof sections of the carriages, down in the vestibule ends where the passenger doors are, and new inter-car jumper cables between each vehicle.

jumper cable

“On top of the vehicle, we’ve also had to put two ‘shark-fin’ antennas, which pick up the signal. Then in each car there are two little antennas, which disperses the signal throughout the carriage.” Ok, so lets work this back and unravel the whole system:

shark fins thumb1. Shark-fin antennas
The shark-fin antennas on the roof of the train pick up mobile signal as the train’s in motion, before sending it down into the main transmitter box (or boxes – there are two in the longer seven-car trains).


box cables2. Booster box
That box then disperses the signal along the cables that run the length of the train, which feed the two small antennas inside each carriage.


inside antenna thumb

3. Internal antennas
Our network signal leaves those antennas and bounces into your phone, giving our customers a reliable 3G signal.


Simple, right? Well, not exactly…

Step by step

That’s how the tech works once it’s all in place, but getting it fitted into nearly 30 different trains wasn’t easy. “It was such a big job that we had to do all the engineering in four separate work packages,” says Paul. The problem here was that, even though Paul’s team could work at lightning pace once they’d got going, it would be impossible to fit the tech into each train in one sitting – that would require taking them off the rails for too long.

“There’s usually 24 trains available for traffic every day, leaving us three for maintenance,” says Paul. “That’s usually one train in for routine examination, and two for ad-hoc repairs or cleaning. Every so many days, a train will come in for an exam – like a regular MOT. That only takes a day and there’s always one being examined, so what we did was went through all the trains and did the first bit of work whilst they were in for exam.”

inside train side

By doing that, our signal-boosting kit could be fitted in stages that didn’t affect any of East Midland Trains’ service. “By the time we’d done that on all the trains, the first one was back in for exam and we could do the next phase. “We couldn’t upset the exam routine,” says Paul, “but if it was a small enough job per package, it was manageable.”

As such, all the necessary jobs were divided into the following packages of work:

1. Fit the internal and external antennas
2. Put the main booster box inside the central cupboard
3. Place and connect all the internal cables
4. Fit the external, inter-car jumpers and test the signal.

“That system,” Paul adds, “meant that the trains were never off the rails for more than their usual one-day exam. The project never hampered the availability of the train.” Sneaky work.

train seat

The result? After almost a year from the very first talk, all 27 Meridian 222 trains are now back on the line with Vodafone’s signal-boosting kit pumping away inside. What’s more, you’d never notice any of it if you didn’t know what to look for, and you’d never have experienced any reduced service during the build.

What you will notice, though, is a much more reliable mobile signal as you speed up and down the country.

Signals in the Shard: How do you push signal into the skies? Find out how we brought reception to the top of London’s skyline.