The best way to have a good idea is to have lots of ideas.
After three attempts to do my silver height, always foiled by logger problems. The opportunity to do it came up again. With only two problems.
1) It was very windy with a constant 25 knots from the south west.
2) The cloud base was only just high enough
For safety I was carrying two loggers, I have learnt my lesson the hard way.
So after the seemingly mandatory first launch which I didn’t get away from, the second launch which I got to a helpful 1700 ft I contacted a couple of week thermals and a lot of sink, before finding a strong thermal above the grain silos at about 1000 ft. Which was pleasing as I had already lowered the wheel.
The thermal was strong but choppy due to the wind, and difficult to stay in. But with some effort climbed to cloud base at 4100 ft a climb of 3100ft a mere 180 ft short of the silver height. Drat and Double Drat. It was only 12:15, two options occurred to me.
1) Try to decent below 800ft and climb away again – unlikely to succeed
2) Try and stay high and hope cloud base continued to rise – more likely to succeed.
I attempted plan 2 but after loosing a lot of height heading off in the wrong direction, and a long battle to stay up if finally conceded it wasn’t going to happen and landed at 13:00.
After asking around I decided to wait an hour and a half, and then have another go, after a delay due to cable problems. I got another launch at 15:40 a little later than I had planned. After 1800 ft launch I immediately entered a thermal, good for going up but bad for silver height as it means that you have a high “low point” also you risk not “notching the trace” which means it is impossible to tell when the launch ends and the soaring begins, this can raise your low point even higher.
Conventional wisdom in this situation is to establish yourself in the thermal, then while still in the thermalling turn open the airbrakes and descend in the thermal. Thus when you close the airbrakes you should be reasonably well centred. Unfortunately for me the thermal I was in was not great and I was being blown downwind too fast for the rate of climb I was getting.
I left the thermal and played around with a number of other gliders, going in a repeating cycle of gaining height, pushing back into wind, only to end up back where I started and repeating the same climb in the same thermal. After half an hour of this all I had achieved was set a low point of 900 ft (very useful) but only ever got as high as 2800 ft. I had been hanging around the west side of the airfield hoping to contact the same thermal I had found earlier, but it was clearly not working. The other gliders I was with did not seem to be doing significantly better, except for a cirrus which shot of (and apparently landed out).
To the east of the airfield a large bank of dark menacing clouds had appeared, I decided that it would either provide great lift or rain, so I boldly decided to head straight for it. My reasoning was that if worked it would be great and if it didn’t I would have ended up coming down soon anyway. I’m rarely right when it comes to predicting the weather, and my bold decisions pay off even less often but in this case I flew straight into a stonking thermal and climbed straight up to 4600 ft more than enough to claim my silver height.
As I climbed I turned on the Vertica to make sure I was well clear of 5500 ft airspace above Gransden, and observed showers in the distance moving rapidly towards Gransden. At cloud base I turned back towards the airfield to see the showers now very close to Gransden and decided it was time to go home.
Lowering the nose I took the glider to 130 knots (5 knots below Vne) it was a bumpy ride as the air was still quite active. I arrived back at the airfield at 3500ft and passed though a patch of light drizzle. Slowing to 80 knots I opened the airbrakes and put the glider into a side slip, I was sinking at 1800 feet per minute a reached circuit height in seconds, my ears popping as I was descending so fast. I performed and normal circuit and just as it completed my final turn the drizzle returned making it a difficult but successful landing.
The paper work was lengthy and dull, but a big thank you to Andrew Watson for sorting it out for me. And yes one by fortunately not both of the loggers failed. The moral of the story is persistence is rewarded in gliding, as I got two long soaring flights and a silver height out of a not very good day.