Two giant tunnelling machines are starting work on a 10-mile tunnel
under the Chiltern Hills in England for the new High-Speed 2 rail line
from London to Birmingham, Manchester, and Leeds.
The machines are named "Florence" for nurse Florence Nightingale and
"Cecilia" for Cecilia Payne-Gaposhkin, pioneering astronomer. Each
machine is 170m long and as they cut away at the rock (chalk) the spoil
is removed by conveyor and sections of concrete wall are inserted behind
the cutting face. They can dig about 15m per day and the job will take
three years. I understand that the concrete wall segments are being
formed on the machine and transported forward to the newly cut rock face
where they are fitted together.
Cecilia Payne was born in Britain and was the first astronomer to show
that stars were more or less all of the same composition, mainly
Hydrogen and Helium and a few percent metals, with the differences in
spectra caused by their effective temperatures and not their compositions.
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