Nimrod Design and Build History

By Jim Mannall

Nimrod 1 - Nimrod 2 - Nimrod 3 - Nimrod 4 - Nimrod 5 - Nimrod 6 - Nimrod 7 - Appendix

Nimrod 1 was completed in March 1968. It was never competitive and was written off in a crash at RAF Chetwynd in March 1969. The definitive Nimrod planform and fuselage shape, later published, was established with the completion of Nimrod 2 in May 1969 which was subsequently flown in the 1969 Criterium of Aces ("Euro champs") at Genk in Belgium. This planform was shared by nos.3, 3A, 4A, 5, 5A and 6. The exception to this was the wing thickness, which was 20% in no.2 and 18% in all later models.

The "mark no's" were unfortunate additions to the published plans in Model Airplane News and Aeromodeller. I prefer to think of them only as a build number, reflected my building sequence. There were of course construction details changed on each version in the continuing search for lightness and strength at the wing to fuselage joint. Later no.5 (and 4) was fitted with a bolt-on tailplane and designated 5A. The first version built new with removable tail was no.7. The next development No.8 has a Super Tigre 46 replacing the Merco 35 and is not yet finished (started in 1977!)

I have tried to give a brief chronology below, which I hope will aid any "vintage or not vintage" deliberations:- N.B. the "paragraph numbers" below refer to all my .35 powered stunters starting with Crusaders (1 to 9), the first Nimrod being 10 in this sequence. Sequence numbers appeared on the fuselage sides, Nimrod build numbers on the wing.

Nimrod 1

10. Nimrod 1. One piece construction. Straight (not tapered) wing 20% section thickness. All 1/16" sheet covered. 3" shorter from wing to tail than subsequent versions. Completed July 1968, blue with white trim. Written off March 1969.

Nimrod 2

11. Nimrod 2. Detachable wing. Tapered. All 1/16" sheet covered. Completed May 1969, Yellow (majority), orange (LE and upper fuselage), black (trim) - this 3 colour "identity" retained for all later models. Wing scrapped -1990 due to wear and tear after years in the loft. Fuselage existing (mates with no. 4 wing - converted for ST 46 in April 1978 - see below).

Nimrod 3

12. Nimrod 3. As no.2 but lighter (only wing LE sheeted). 18% wing section thickness. Completed March 1970, white, light blue, red.
1970 Gold Trophy winner.
Refinished March 1974, white, light grey and red, numbered 3A. Scrapped ~1990 due to wear and tear etc.

Nimrod 4

13. Nimrod 4. As no.3 but with tapering thickness wing section in order to match with no.2 fuselage - root 20%, tip 18%. Originally twin finned (after Tupker's Olympus). Completed June 1970, yellow, red, blue. Changed in march 1971 to single fin. Rebuild after crash in early 1972 with detachable tailplane. Recovered in Silver Solarfilm, blue LE and red trim numbered 4A (No known photos).
1972 Gold trophy winner in this modified form.
Wing re-finished April 1978 together with no. 2 fuselage (ST 46 fitted), yellow, blue and black (as no.5A) and numbered 4B. No.4 Fuselage and tailplane scrapped ~1990 due to wear and tear etc.

Nimrod 5

14. Nimrod 5. As no.3. Completed January 1972, white, grey and red.
1973 Gold Trophy winner.
Rebuilt after crash in March 1974, yellow, blue and black and numbered 5A. After 2nd crash in practice at 1974 Nationals rebuilt again with detachable tailplane (still numbered 5A).
1979 Gold Trophy winner in this modified form.
Existing but covering damaged after years in storage.

Nimrod 6

15. Nimrod 6. Larger canopy, lower and longer fin. Completed June 1973, white, red and black.
1973 Jura Cup (Breitenbach) winner.
1975 Gold Trophy winner.
Written off early 1976 after crash.

Nimrod 7

16. Nimrod 7. Wing plan changed, tip chord reduced by 0.5 inches to increase LE taper. Tailplane centre chord increased by 0.5 inches. The first to be built from scratch with detachable tailplane. Completed April 1976, white, light blue and red.
1978 Gold Trophy winner.
Existing.

Appendix. All my competition models were allocated a serial/sequence number which appeared on the fuselage side number as follows:-

1. Crusader 1. January 1962. Blue (most of wing, tail and lower fuselage), Red (LE's and top of fuselage), white (trim).

2. Crusader 2. April 1962. Yellow, Orange, Black (scheme as no.1). Tricycle U/C.

3. Cruseder 3. Early 1963. Colours as no.1.

4. Crusader 4. Monowheel with outriggers. Orange, Blue, white

5. Crusader 5. April 1963. Colours as no.1.

6. Crusader 6. March 1964. Dark green, crimson, white (scheme as no.1).

7. Crusader 7. 1965 (?) As Crusader 4.

8. Crusader 8. Early 1966. Much lightened. Yellow Tissue, Blue fuselage and wing LE.

9. Crusader 9. (Wrongly numbered "8" on fuselage!!) completed 1966 (?). Much lightened. Yellow Tissue, Red fuselage and wing LE.
1968 Gold Trophy winner.

10 etc. Nimrods - see above.

N.B. Crusaders 4 and 7 were rebuilt from the 2 halves of a a twin, similar in principle to the Twin Mustang concept. This was 76 inches span, weighed 95 oz (!) and flew on 100 ft lines. Impossible to transport - never seen outside Lincoln.