Group captain Herbert Massey, as senior British officer, authorised the escape attempt which would have good chance of success; in fact, the simultaneous digging of three tunnels would become an advantage if any one of them was discovered, because the guards would scarcely imagine that another two were well underway. The most radical aspect of the plan was not the scale of the construction, but the number of men intended to pass through the tunnels. While previous attempts had involved up to 20 men, in this case Bushell was proposing to get over 200 out, all wearing civilian clothes and some with forged papers and escape equipment. As this escape attempt was unprecedented in size, it would require unparalleled organisation; as the mastermind of the Great Escape, Roger Bushell inherited the codename of "Big X". More than 600 prisoners were involved in the construction of the tunnels.