The new range of PPE for female staff includes high-visibility jackets, trousers, gloves and adjustable eye protection.

A tailoring service will ensure workers will have access to better-fitted, safer Personal Protective Equipment.

Safety boots designed exclusively for TfL’s female staff are also in development and set to be introduced in the New Year.

A six week trial on site found that many women have for years resorted to safety pins or rolled up trousers to make universally-sized PPE fit them.

Melanie Ogden, Northern Line Extension Tunnels and Shafts Project Manager, said: “Finding PPE that fits has always been a challenge for women in engineering, whether it’s rolling up sleeves, holding up trousers or having to wear multiple pairs of socks just to keep our shoes on.

“A ‘one size fits all’ approach for men and women hasn’t worked, which is why it’s great to see TfL taking a lead in this area.

“Taking part in the trial to source new women’s PPE has been enjoyable and has resulted in comfortable clothing that allows us to move more freely and work more effectively.”

Miles Ashley, London Underground’s Construction Programme Director, said: “Transport for London is committed to increasing the numbers of women working in engineering and construction.

“While we have a more diverse workforce than ever before, feedback from our staff tells us that our PPE has failed to keep up. It’s clear that universally-sized PPE isn’t fit for purpose for our female staff, and we’re keen to get it right.

“That’s why we’re introducing new safety clothing that has been designed specifically for women and are working closely with our staff to broaden the range to include safety boots too.

“London will need more engineers by the end of the decade to build the critical infrastructure we need, so it’s important that we take every step we can to make construction a more welcoming environment for all.”