Inside Box Tunnel
Great Western Railway uses Brunel’s birthday as the perfect opportunity to test a great railway myth…
GREAT Western Railway used Isambard Kingdom Brunel’s 211th birthday on April 9 as the perfect opportunity for investigating one of the railway’s greatest myths - did the engineer design Box Tunnel so that the sun shines directly through the structure on his birthday?
The two-mile structure, near Bath, has long been the subject of this belief, and GWR decided to test the myth. The operator said that engineers and mathematicians had previously concluded it could be true, with calculations published in New Civil Engineer magazine and elsewhere.
GWR confirmed that the tunnel does align with the rising sun, and that the sun does light up a significant section of the tunnel. However, despite the sunny conditions of April 9 this year, the sunlight did not make it all the way through the structure.
“The alignment of the sun directly between the tracks makes it difficult to imagine it wasn’t engineered. Given that the sun rises in a slightly different spot from the east each day it’s hard to predict the days with pinpoint accuracy,” said GWR Commercial Development Director Matthew Golton.
“That said, Brunel might have calculated it right - when building the tunnel his calculations were so accurate that when the two ends joined up it was only five centimetres out. But he may not have taken into account leap years, and so the sun effect has moved away from the actual day of his birthday. Take a look at the photos and draw your own conclusions.”
GWR took the opportunity to test the theory this year because a possession at Bath meant there was access to the railway.
Inside Box Tunnel on April 9 (Isambard Kingdom Brunel’s 211th birthday), engineers try to prove if the sun does shine through the entire structure on Brunel’s birthday.