Water ballast is carried in tanks or bags inside the wings and sometimes in the tail fins of gliders in order to temporarily increase the weight of the glider for a particular flight. This water ballast is generally jettisoned before landing. By carrying water ballast the glider achieves a higher speed around a task and allows the glider to penetrate into wind easier than one without water.
Advantages:- Allows the pilot to complete his task quickly and get back down on the ground as soon as possible to tell all his mates how well he has done.
Disadvantages:- Allows the pilot to complete his task quickly and get back down on the ground as soon as possible to tell all his mates how well he has done.
Like most subjects, views differ, but nailing my colours to the mast here, water ballast is a massive disadvantage. I mean, why would you? I vaguely remember my physics teacher telling us that you can’t get something for nothing. Well he didn’t phrase it exactly like that but you know what I mean. And he must have been right, otherwise those nice people selling heatpumps would have sold out by now.
I’ll admit I’m no physicist. As an eleven year old on my first day at the big school, sporting my new long trousers, I was handed a lesson timetable. Most of the contents I understood: maths, English, PE, chemistry, biology, metalwork, woodwork etc. However, there was this thing called physics and I hadn’t got a clue. Obviously all the other kids knew exactly what this subject was, because no-one, and I mean no-one said anything. Did I ask? Are you mad? Of course I didn’t, I just packed my plimsoles in my rucksack just in case. I may have digressed here slightly but bear with me. This was the late 1960s and in those days the education system did a good job of preparing you to be something you’d not thought of. None of that, you can be anything you want to be, nonsense.
As a consequence of this well grounded education I didn’t need to be a Nobel prize winning physicist to work out that water ballast is hard work, I just needed to be able to observe, evaluate and conclude.
Observation:- From my vantage point of enjoying a morning coffee having rigged my Libelle I could see my friends arriving in their cars with the tailgates open revealing 4 or sometimes 6 large water containers. There was only one tap. This filling process took some time and then they’d drive back to their gliders allowing the next in line access to the tap. After another lovely coffee I’d wander out to find that if I thought the tap wasn’t the fastest means of dispensing water, it wasn’t the slowest either. Filling the glider was going to take some time and there was nothing I could do to help so I might as well go and fly the task.
Evaluation:- Fast forward to me landing back, admittedly this didn’t happen all the time, and there were all my friends looking quite downbeat, except for one who was extremely happy: the fastest round. So water ballast only made one person happy. But without the effort that is water ballast I was also extremely happy. Just getting back and being in the air for hours is what made me happy.
Conclusion:- Don’t buy a heat pump.
