Earlier this week I was lucky enough to be invited to a press & bloggers site visit of the construction of Crossrail’s western tunnels. This is happening between Royal Oak and Farringdon and is a joint venture between BAM Nuttal, Kier Construction and Ferrovial Agroman. Although it will be a few years before Crossrail appears on the London Underground map I was pretty curious (to say the least) to see what was going on.I'd never visited the construction of a railway before and it was quite an amazing sight to see the Tunnel Boring Machines (TBM) and the level of activity taking place at the Westbourne Park site where over 150 people are working.I was too busy taking gawping at the machines, taking photos & tweeting to take too much notice of the technical stuff. Also with protective gloves, a hard hat, goggles and slightly oversized protective shoes it was hard to take notes. So here's the low down of the progress from Crossrail themselves.."Apparently each TBM is like an underground factory and as they move forward, precast concrete segments are assembled into rings which line the tunnel behind the TBMs.A total of eight tunnel boring machines (TBMs) will construct 21km of new twin-bore tunnels (42km in total).So much for the facts and figures. What was it like being there? Strange & fascinating. In the saftey briefing beforehand the Crossrail staff made sure we knew what hazards to look out for (not that we needed to be reminded as there were tons of warning signs everywhere).They were also at pains to tell us how clean & tidy the construction site was. Now everyone knows the phrase "" implying that something is going to look a mess. But once we got to the site, I discovered they were correct. There was not one piece of litter. It almost looked like a film set of a building site.Once I got used to walking around with a hard hat on, I could take in more of the atmosphere. The workers all seemed reasonably happy, and everyone I saw was actually working and not hanging around smoking fags or looking into holes or tunnels scratching their chins and shaking their heads saying "", which is my general experience of constuction workers.The guys who showed us round were also keen to point out that there hadn't been an accident since work had been started on the site. The site is up for a Considerate Construction Site Award which I reckon they stand a good chance of winning.Health & safety was definitely rigourous and I did see a number of workers making some of these hand signs when cranes were moving enormous tubes, girders and other tunnelling equipment around the site.You can see the full set of pictures from my Crossrail Site Visit here.Also John Bull from London Reconnections was on the visit with me and has a great post with a more photgraphs too. Although we weren't given a date as to when the first tunnelling would start, he said "."I'd like to thank the team at Crossrail for inviting me along and also for their patience on the tour. It can't be easy herding a team of bloggers and photographers around a construction site.