1: Gulf expressed in certain letters (5)
4: Incredible disorder in fat cats (9)
8: Logical oil Polish chap applied (13)
11: Incomprehensible English is the sign of a professional (7)
13: Biggest rat's leg is broken (7)
15: To live with a former partner is the final result (5)
16: Uneven ships cable made from hemp (5)
17: Trains without commanding officer and suffers (5)
19: Has great success taking in an unspecified number of intimates (5)
20: Clean oneself, but in reverse (3)
21: Strike one with medium iron (7)
22: Dexterity is an insult, so we hear (7)
24: 3-down said Sir, I have these! (5,4,4)
26: Praised a general capturing returning traitors (9)
27: Going back in where GI trapped predator (5)