Local labourers were employed on the site, as were forced workers from Belgium and other countries. Whilst one accident was reported in the Evening Post newspaper on 6 February 1942, it’s understood that, thanks to the good reputation of the contractor, the tunnel was a comparatively safe working environment. That is more than can be said of other tunnels excavated nearby, including Ho8 – now known as Jersey War Tunnels. 

Such was the volume of shale excavated from the tunnel, and another tunnel on the other side of La Route de L’Aleval, that a pile of spoil formed in St Peter’s Valley below, rising to the height of the valley itself. Ammunition was moved into the complex in May 1944, and by the end of the Occupation around 6,000 tons of it was stored within.  

At the time of the Liberation, the British Army used the tunnel to dispose of German hardware which was crammed inside and sealed up, only to be extracted in the early 1950s by scrap merchants.  

Over the years since then, the complex has been used for the storage of hire cars and coaches, as a rifle firing range and for growing mushrooms. 

Just a short distance further up La Route de L’Aleval, on the right hand side, are the unmistakable cast concrete remains of a stone-crushing device, used to process rock into fragments for building aggregate.