Salthook is a small mining town that appears at the very beginning of Mortal Engines. It appeared to mine the salt from the old sea bed. Hester Shaw had been living on it. The air traders fled the town when they knew the chase was up. It is unknown if anyone who actually lived on the town escaped via airship. London ate the mining town, and it was digested in the Gut. Whilst its citizens were being prepared to be integrated into London society, Hester Shaw tried to kill Thaddeus Valentine but was stopped by Tom Natsworthy.
Salthook had C-20 land engines and could reach 120 MPH, and seemed to have anything from two to four tiers; probably three judging from the official artwork.