Wednesday, December 09, 2015
We are back off the water after the second of our testing sessions. Please see below our observations;
Wind; SSW 10-12knots. SSW with shifts of around 10 degrees. With the direction of the breeze off the south bank of the Blackwater there were some shifts that were sufficient to abort some test runs as they compromised the results. The breeze was gusting frequently.
Tide; 0.5 knots ebbing.
We managed a lot of long port tack upwind legs with alterations in positioning of 881 and the Rondar boat to windward and leeward and after around an hour of sailing swapped crews.
We were predominantly sailing long port tack legs ( up to 9 minutes) due to wind direction. We did only one starboard tack leg just to verify there were no differences on the other tack ( which there were not).
Sea state was mainly flat with a small chop of less than 0.25m.
Following the previous test Malcolm H had spent 3 hours measuring the two boats to address the issue of restricted mast bend on the Rondar boat. Previously although set up with similar measurements , the rigs were different because of the variation in mast heel height. This was rectified by moving the mast foot one hole. We sailed with rigs that were now very similar in most characteristics.
There were still some differences ; the spreaders on the Rondar boat were longer by one hole. The new mainsail on the Rondar boat had a slightly more open leach due to use and age. The mainsail on the Rondar boat was still slightly fuller probably due to the lowers being 1/2 to 1 hole too tight compared to 881.
The first run we opted to conduct in "race mode" i.e. we sailed with the sheets and control lines in the positions we would choose to race in and hiked to keep the boats at our best angle of heel. We abandoned this after a few minutes because the extra variables distracted from the goal of identifying differences in the hull.
From that point on we set the barber haulers, jib sheet, traveller, vang and mainsheet in the same position in both boats.
Over two hours of sailing we found and all agreed, that 881 was still quicker on every upwind leg regardless of who steered.
The differences were less than on fridays test. They were in the order of around 1 boat length gained in VMG over 5 minutes of sailing.
We tested the boats on a dead run with spinnakers up in sub planing conditions and 881 gained about 1 boat length in 5 minutes.
We tested the boats reaching with spinnakers up on a reasonably broad, non planing reach and saw virtually no difference, but would not regard either the duration of that test or the methodology as very conclusive -other than spinnaker gybing the new boat was no more difficult with the raised floor on the new boat than 819 or 881.
Our conclusions ( which we all agreed) were that we had successfully narrowed the gap in performance - in the conditions we carried out the test. However there was no doubt that the boat performs differently.
In the conditions, pitching was not an issue ( unlike friday) but the Rondar boat powered up more quickly . In gusts it heeled more quickly albeit that did not easily translate into better speed. It was probable that the crew in the Rondar boat had to hike earlier and harder than in 881.
We are confident that with more testing we could tune the boat to get close to the performance of 881. But that differences would exist between the boats due to the fundamental difference in construction.The inevitability is that when performance was optimised, as it probably is on 881, there would still be differences between the boats, some positive and some negative depending on sea state, wind speed and crew weight. It boils down to the new boat having a different "character" to the existing boat. In a boat as "touchy-feely" as the Squib all of you, I am sure , will appreciate and understand the subtle differences - after 6 hours of intense comparison we are confident the boat feels and behaves very differently.
We would not recommend further performance testing until the final construction material and design is agreed because we felt it would be entirely pointless. If the boat was produced as tested today and on friday there is a material difference in performance. Almost certainly attributable to the extra stiffness of the boat ( either structurally or in panel stiffness)
The floor design is felt to be beneficial in respect of the self -draining aspect working ( although the boat had collected water at the front in the marina) and there was no problem with the boom height and floor height for the crew or helm. Jack considered the crew seats were more uncomfortable on the new boat due to their narrowness and the deck position relative to the small of the crew's back and thought there was a slight feeling of less security for the crew on a run as when sat in the boat there is nothing for them to "hook their legs under".Malcolm and Andy thought the crew seats worked well and liked them.The new cockpit is clearly safer in the event of the boat being swamped, almost certainly being able to be rescued by the crew without outside assistance.
The traveller in its forward position was considered to be an unqualified improvement. Possibly slightly too far forward and maybe the best position would be half the difference forward .
We discussed at some length after the testing whether we should confine our comments to just objective observations . We wondered whether it was our "business" to venture beyond that and add any opinions. However on the basis that are views are just four opinions , albeit informed by the privilege of having sailed the new boat comparatively and can be dismissed and ignored by those wiser and greater than us;-
Your testers would suggest that the Technical Committee ;
1/ Agree the construction material with the builder and revise the interior layout to produce a hull from conventional laminate instead of foam sandwich.
2/ The foam floor construction that provides a water tight buoyancy tank and self draining , lower maintenance boat should be retained.
3/ The side tanks and seat design are more difficult- they look better, are not convincingly more comfortable and probably contribute a lot ( as massive "I "beams ) to the extra structural rigidity of the new boat. The Technical Committee might want to reconsider these.
4/ There would be no speed difference in moving the track , but the boat would be easier to tack.
5/ The foam sandwich deck should probably be retained as its extra stiffness stops the deck distorting and probably does not contribute significantly to the overall structural stiffness .
6/ They encourage as many people as possible to sail the new boat to provide feedback on the layout and appearance.
We have learned that a stiffer Squib is a boat that performs differently to the current Squib, perhaps surprisingly it is clear you can make a "Squib" too stiff ……
If these changes were made (in a way that enabled retrofitting of the new deck and floor mouldings) the basic hull ( and therefore character) would remain the same as 881 and we would be surprised if the speed differences we have noted would either exist or be as marked.
Further testing at that point in the development would then be a constructive step forwards.