ACROSS

* indicates anagram

1. Henderson RE - a ROYAL ENGINEER
10. OXIDISERS: OX (beef) + IS around rides*
11. I'M A GO (Latin for 'image')
12. VOICE: v(ersus) 0 (no) ice (diamonds), so for them
13. NEIGHBOUR: homophone for 'nay bore'
14. CHIRPER: CHI + lette(R) + PER (for); if it chirps, it flies
17. GAOLERS: OLE inside GARS (garfish)
20. EL: Arabic definite article and 12th letter of the English alphabet
21. MR: abbreviation for mister
22. DULOTIC: (soldier) ants may enslave other creatures to work in their nest
24. PISCINA: Latin for bath - PI + S + Inca*
25. PASSIONAL: Asian slop*
27. SNOOT: not OS*
28. TORSI: riots*
29. HARMONICA: HARM + a coin*
30. CRIMEAN WAR VET: writer caveman*

DOWN

2. ORIFICIAL: R(hode I(sland) inside OFFICIAL minus one F
3. ALIKE: lake I*
4. ELEANOR: E(nglish) (David) LEAN + OR
5. GOSLING: double definition
6. NEIGHBORS: 'Homies' indicates American spelling of homophone of 'horse talk + tedious'
7. ERATO: a muse - ER (um) + A + TO (prep.)
8. CONVICT DEPOTS: noticed Scot VC*
9. COURTS MARTIAL: COURT (woo) + SMART (clever) + AL (capone) with one (1) inside
15. PETRINISM: (doctrine of St Peter) PS interim*
16. ELI: rough homophone for 'he lie'
18. AMI: AM + I - friend in Nice is 'ami'
19. EPITOMISE: poise time*
23. CYNTHIA: in yacht*
24. PILCROW: PIL(L) + CROW
26. SORER: SO + RE + R
27. SHOER: (a smith shoes horses) - HOE inside SR

ACROSS

1. Re Sir Edmund Henderson, say (5,8)
10. Beef is about upset ride's air fresheners (9)
11. Mullet's a starting image (5)
12. Speak for diamonds (5)
13. No drill heard next door (9)
14. Letter's last for flyer (7)
17. Turnkeys find cheer in fish (7)
22. Of enslaving by soldiers? (7)
24. Letter's changed Inca in ancient bath (7)
25. Asian slop stirred in emotional way (9)
27. Big nose? No, not OS (5)
28. Trunks make riots (5)
29. Damage bent a coin instrument (9)
30. After struggle, chap's a crazy writer, caveman (7,3,3)

DOWN

2. Of an opening: authoritative, state inside not following (9)
3. Similar to lake I swim in (5)
4. English film director or English queen (7)
5. Ryan's a little goose (7)
6. Homies' horse talk is tedious, by the sound of it (9)
7. Um, a preposition maybe amuse (5)
8. Hire a TOL man here, having maybe noticed Scot VC (7,6)
9. Military judges woo clever gangster with one in (6,7)
15. PS: interim confused senior apostle's doctrine (9)
16. Priest's not telling the truth, I heard (3)
18. Do I exist, nice friend? (3)
19. Stand for poise time exercise (9)
23. Moon goddess in yacht abandoned (7)
24. Paragraph mark nearly a tablet for raven (7)
26. Thus on king hurting more (5)
27. Smith's tool in southern region (5)