TURNING HEADS.

Designer Jason Ker comments on IRM, IRC - and also on his very quick IRM 35, Roaring Meg.

Our IRM 10.7, Roaring Meg, is a development of our existing IRM 9 metre, Quokka 5/Shakermaker 2. The low centre of gravity and narrow waterline were made possible through the engineering of John Levell and good construction, while the TNZ-inspired rig gives the rating advantage of two spreaders with the lateral support of almost four, allowing a narrow mast section and shroud envelope.

Arriving at Cork Week two days after launching and with absolutely no work-up, we found ourselves racing in IRC class zero against the likes of Pyewacket and fighting on the water with Farr 40s, so were very pleased to be placed seventh overall in class, splitting the Farr 40s.

However, losing the rig in 35-45kt of wind on the return trip dashed work-up plans for Commodores' Cup. But C-Spars pulled out the stops and a new rig was stepped three days before the event. The first race took place in light air, which Roaring Meg excelled in, winning her class by a large margin and sailing the slowest boats out of time. The second race followed a similar vein, with her beating half the F40 fleet on the water. Unsurprisingly, bar-opinion was that the boat must be a light wind-flyer and would surely fall over in a breeze. With 20kt the next day, the crew were delighted to take another convincing win. beating four F40s on the water.

Heading off on the 24hr offshore race, Roaring Meg was leading the regatta overall. But while rapidly overhauling the F40's in the fresh upwind conditions, a loud crack signalled the end of the boat's regatta, leaving smaller sister Quokka 5 to take the race.

Post mortem: Following the failure of a second mast, C-Spars commissioned John Levell to investigate. After a Finite Element study, that tested some very large variations in tune, it transpired the rig had been considerably lacking in pre-tension. The study concluded that it should, when correctly tuned, be robust. Thus one of the same geometry will replace the broken one, though rig tune will be the product of more science than before!

The RORC rating office looks likely to increase the penalty slightly on runners next year, to widen the appeal of IRM to those who want IRM speed but come from a background of runnerless boats. Our new Ker 11.3m IRM One-Design takes full advantage of this rule tweak, with its non-overlapping, runnerless configuration.

Relative performances: To illustrate the sheer speed of a state-of-the-art IRM design, one can see that the 35ft Roaring Meg was continually mixing with the Farr 40s all around the course, and finishing an average of five and nine per cent ahead of the ID35 and Mumm 38 respectively. These margins did not vary much whether the conditions were light or strong and in Class A the first six races were won by new IRM designs from our office.

Summary: Those who sailed the 2000 Commodores' Cup were left in no doubt as to the potency of good IRM yachts in absolute speed terms, but some may not yet be aware that IRM yachts can also be very competitive in IRC. The potency of a suitable IRM design under IRC was demonstrated by Shakermaker's emphatic win in Cork Week's 46-boat IRC class 2, beating a well-sailed Swan 48 into second place overall and winning three of her four wins with line honours. Although amusing for a 30-footer to be tussling on the water with a yacht 18ft longer under IRC, it was far more of a joy to race a fleet of fast, light yachts under IRM, where far closer and more meaningful racing took place between modern racing yachts. And with the IRM typeforming rule no 'Beachballs' or S&S classics were able to gate crash the party.