With its huge size and wheelbase the U1 rode well and a commodious cab was provided. Unfortunately this did not help when negotiating the two Silkstone tunnels just before the top of the Worsborough Bank. Being the last of three steam locos to enter the tunnel the atmosphere on the footplate with heat, steam and smoke was "close to hell". To try to overcome this, gas masks were provided for the crew connected via a pipe to a vent at rail level, but the crews objected to sharing these for reasons of hygiene and continued to use the time-honoured method of covering the nose and mouth with a wet handkerchief.