Our library and archive centre is a busy part of the museum. Our visitor numbers show that we’re helping more researchers find the answer to their questions every year. But sometimes we’re contacted by researchers who can’t make the journey to the museum –and that’s why we’ve introduced the Inreach service. In return for a donation of £20 you can hire an expert volunteer researcher for a day to search through our collections and find answers to your questions.
Recently the Inreach team got excited when we were presented with an interesting challenge. One of our enquirers wanted to verify a fact he had heard about the A4 Pacific class of locomotive – like Mallard, built by the London & North Eastern Railway (LNER). The story goes that the locomotives were so fast that the LNER’s civil engineers became scared that the trains might start ripping up the track and cause an accident. They demanded that speed recorders were fitted (similar to a speedometer in your car) to a whole class of locomotive for the first time in Britain.
It might be a surprise to anyone that hasn’t seen a steam locomotive footplate before that very few British locos were ever fitted with anything like a speedometer. Judging the speed of the train was done purely through the driver’s skill, using his route knowledge and mileposts next to the track. This is despite the fact that speed recording equipment had existed for decades. Indeed, in France, 80% of locos had been fitted with a Flaman speed recorder by 1914 – 21 years before the first A4 was built.
Unfortunately the story about the engineers’ fear of the A4s wasn’t going to stack up. Although it’s clear that all of the A4s were fitted with the speed recorders from new, it wasn’t the first time that a whole class of locomotive had been fitted with them on the LNER. In 1934, Sir Nigel Gresley designed the P2 class for express trains between Edinburgh and Aberdeen. The first of the class, Cock o’ the North, was sent to France after it was built to be tested at Vitry near Paris. To run on the French railways it needed a speed recorder, so it was fitted with one called a Telos from a London firm called the Hasler Telegraph Company. It was decided to fit the other five locomotives in the class with one – probably to prevent drivers speeding on the tight curves of the line to Aberdeen. Since the last P2 was built five months before the first A4, Silver Link, was completed, we had proven the A4 theory wrong.
We did however find out one interesting thing about the A4s in our research. The Silver Jubilee was a streamlined train, first hauled by the A4 Silver Link between London King’s Cross and Newcastle. The LNER’s staff magazine reported after the first running of the train that:
“a novel fixture is the electric speedometer which has been installed in the first-class restaurant car for the convenience of passengers interested in the running of the train”.
This wasn’t the end of the story though. The book Our Home Railways, How They Began and How They Are Worked by W J Gordon in 1910 (follow the link to the free E-Book) when referring to the London, Brighton & South Coast Railway (LB&SCR) mentions that “every Brighton engine has, in the cab, a speed indicator”. That was 25 years before the LNER finished the P2s. This clearly needed further investigation.
In his presidential address to the Institution of Locomotive Engineers in 1948, Lt-Col Harold Rudgard credits William Stroudley with the invention of a speed indicator1. Stroudley’s speed indicator was a novel design. A fan was driven from the axle of the rear trailing wheel by a belt. This pumped air into a gauge glass on the footplate. Higher speeds would force a ball sat in the glass upwards and this could be read against a gauge next to the glass.
Our attention soon turned to the London, Brighton and South Coast Railway Class G – designed by William Stroudley. The first of Stroudley’s speed indicators was fitted to locomotive Grosvenor, built in 1874. 13 more locomotives were ordered with some modifications, the last being delivered in 1881. Of course the fitting of the speed indicator to the prototype could have been a one-off. so the clincher came in the form of two images we found. The first was a photograph of No.336 Edinburgh, clearly showing the speed indicator fitted to the frames behind the single driving wheel. The second was a set of drawings in our archive showing Stroudley’s patented speed indicator. One drawing shows the speed indicator as fitted to No.350 Southbourne (below).
From this we can be fairly certain that speed indicators were fitted to the whole class from new, and we believe this was the first time this happened in Britain. This was in fact 60 years before the LNER fitted its P2s with speed recorders, and even 27 years before the French patented their Flaman speed recorder. The LB&SCR continued to fit speed indicators to its locomotives. Indeed, one survives in the National Collection as fitted to Gladstone, and you can see it in Station Hall:
Of course, it’s nearly impossible to say how many accidents or lives could have been saved if the speed indicator had been fitted to other locomotives in Britain in addition to those on the Brighton lines. We can’t see an obvious reason why Stroudley and the LB&SCR introduced them when we can find no other pre-grouping company2 that decided to use them.
By the way, if you know something about speed indicators that we’ve missed or of other uses of speed indicators before the LB&SCR Class G, let us know by commenting below. For more about the Inreach service or if you have your own enquiry, see our enquiries page for advice and contact details.
1 A quick note: Stroudley didn’t invent the first speed indicator. We have one in our collection that was made in 1858, but we have no idea where it came from and we believe it was a one-off.
2 Except for the London & South Western Railway, which from our drawings collection appears to have tried a few speed recorders around 1909, but still much later than the LB&SCR.