Tuesday, 17 July 2018

Bladder

A few weeks ago I was sailing in a Salcombe yawl with my brothers. We were on the water pretty much all day, we only came ashore to drink a few pints and buy pasties in the middle of the day. By the middle of the afternoon a practical matter of seamanship had become pressingly urgent. How do you pee off a Salcombe yawl? The curvature of the hull means that you can't stand anything like close enough to the side to aim over the gunwhales. The stern decks is too wide and there's a mizzen sail in the way. The boat isn't big enough or stable enough to stand on the side deck. My brother managed to half-stand-half-kneel with one foot inside the boat and one knee on the side deck, it just about worked but it was awkward and ungainly. I was told to go into the bailer and then tip it over the side. Initially this seemed luxurious – I could turn by back on the rest of my family and lean against the mast for support. I discovered soon afterwards that the bailer was about 10% smaller than the capacity of the human bladder. "Two bailer" is now a colloquial term for the highest level of urinary urgency.

Richard "stem the flow" B

Tuesday, 10 July 2018

Bleeding Brakes!

It was my birthday last week. With characteristic eccentricity my mother didn't just give me a keepsake to mark the occasion. She wanted me to have something that I would genuinely like and realised that she wouldn't know what to buy. Instead she gave me a cheque and the task of both cashing the cheque and buying my own present.

I work nearly full time and the nearest bank that is open on a Saturday is a 15 mile round trip from my house with difficult parking, I wasn't delighted about the "chore" component of my present.

This is what she eventually gave me.

It's, not a hookah pipe, it's not a bong, and it's not some sort of marital aid. It's a manual pressure bleeder for the brake system in a car. Ordinarily you need either a friend, an airline, or a spare tyre. With this system you half fill the vessel with brake fluid and pump it up to 10psi or so. It screws onto the master cylinder reservoir and then you have the whole system under pressure and the fluid being constantly topped up. You can bleed the brakes perfectly without assistance and changing all the fluid in the system becomes the work of minutes. It's just what I've always wanted – for the last few weeks since my friend lent me one.

Richard "billy-no-mates" B

Monday, 2 July 2018

Brakes!

A few weeks ago I was on a track day at Donnington Park on the GP circuit. Even in my little underpowered car we were approaching the Melbourne Hairpin at around 115mph and needed to scrub off about 90mph before the corner. You find yourself rather busy for two or three seconds: Press the brake firmly with the toes of the right foot; clutch down; gear lever into third; left hand back to the steering wheel; press and release the accelerator with the heel of the right foot; clutch up smoothly; clutch down; gear lever into second; left hand back to the steering wheel; press and release the accelerator; clutch up smoothly. And that's all before you've started thinking about turning the wheel.

During my frantic flailing at the controls I would often make a mistake with the gear lever and either grind the gears or end up in the wrong one. My passenger is a good friend who has devoted nearly 40 years to good natured piss taking. The car is a loud environment and the motion is quite violent, but he was still able to shout things like "Try Second" or "It's a standard H pattern" as I approached the hairpin.

On the same weekend I was lent a fantastic book called "How to Drive a Car" which was rescued during the clearance of my sister's late godmother's house. It was published in 1950 and it's so dated that it has become funny to read, it talks about cripples in invalid tricycles and nursemaids pushing perambulators with their human cargo.

Here are a couple of paragraphs:

"Who has not in the past seen many a suffering motorist going through barrel organ motions at the front of his car in often unsuccessful effort to wake it into life, and possibly in the process receiving a sprained thumb or wrist? Luckily those days are almost gone, for modern self-starting mechanism, electrically operated, is now incorporated that makes it possible for even the frailest feminine hand to start the most powerful engine by merely pressing this knob."
"Many years ago the authors used to advise would-be motorists to thoroughly master double de-clutching with no more complicated equipment than a piano, a flower pot and a walking stick!"


Richard "Learn to Drive" B

Thursday, 28 June 2018

Holiday

I've just come home from a family holiday in South Devon. We stayed in an Airbnb and hired a little sailing boat. The boat was a joy and the house was like a brilliant scavenger hunt. If you looked hard enough you could find almost anything you wanted. Crabbing equipment, camping stove, parasol, tablecloth, spare light bulbs, weighing scales, board games... There were 2 exceptions. We never found the salt and pepper (although we all think that it was in there somewhere and we just hadn't located it) and there were no towels.

The main theme of the holiday was not being dry, despite staying over mid-summer's day during a heatwave. The house is built into the shady side of a hill beside a creek, it doesn't have good ventilation and everything associated with it is slightly damp. We all thought we might catch mildew or mould when we went to sleep. After going and buying a towel my sister-in-law had a bath and the bathroom ended up so steamy and covered in condensation that she was actually unable to get herself dry afterwards.

Some of the roving on our little boat had gone loose and water was constantly weeping inwards – to the extent that the owner had fitted an automatic electric bilge pump and a big battery to keep the thing afloat when it was on the mooring. It worked perfectly and fitted in nicely with the theme of our holiday.



Richard "Poacher's Pocket" B

Monday, 18 June 2018

Book Review

Ignition!


I have just read "Ignition!" by John D. Clark. It's an informal history of liquid rocket propellants and while it's a great read I'd have probably enjoyed it more if I had a degree in chemistry. Some great authors send multiple characters (or generations of characters) through similar trials, or have recurring themes that affect all the characters. (I'm looking at you Hugo, Dumas, Tolstoy, etc.) In Clarke's book  you get something similar, but the characters are hard to relate to and have difficult names like C-stoff, S-stoff, N2O4, Mixed Oxides of Nitrogen, Inhibited Red Fuming Nitric Acid and Unsymmetrical Dimethyl Hydrazine. The recurring themes are eutectics, equilibrium mixtures, toxicity, corrosion, unacceptable freezing points and the tendency to explode unexpectedly.

Asimov writes a gushingly complimentary foreword and compliments Clarke's short stories handsomely. Ignition is also really fun to read, it contains some great stories, and wicked phrases.

I learned most from the chapter on rocket performance and I now have a much better understanding of Specific Impulse. It's normally defined as the thrust of the rocket (in pounds) divided by the rate that the rocket consumes fuel (in pounds per second). It comes out in seconds. I've never been particularly happy that the quality of a rocket motor is measured in time, but I have manage to justify it to myself by thinking that it's sort-of how long a rocket could hover before it runs out of fuel. Clarke shows us that it's a ridiculous measure brought about by the horrific ambiguity of force and mass in American scientific units. If you just apply Newton's Laws, common sense, and basic algebra you can see that all the fuel being consumed is coming out the back of the rocket (or there's something badly wrong with your design) and that the force applied to your rocket is the same force that's accelerating you exhaust stream.

Specific impulse becomes the velocity of the exhaust of a rocket divided by the standard acceleration due to gravity. Clarke correctly points out building a rocket whose sole purpose is to get away from earth and then expressing its exhaust velocity in terms of the gravity of earth is "parochial and extremely silly". He prefers to think of Specific Impulse as a velocity expressed in units of 32 feet (or 9.8m) and while that works well it offends my dimensional analysis sensibilities. I now think of Specific Impulse as the length of time that a stone dropped in a vacuum takes to gain the same velocity as the exhaust stream.

The book is rather dated. It doesn't cover any developments past the late 60s and it amused me when he talked about Boron Nitrate and discussed the theoretical possibility and the early research that suggests it might have a hard cubic form analogous to diamond.

Richard "8 out of 10 would read again" B

Monday, 11 June 2018

Synchronicity

A couple of weekends ago I took my sports car to a track day at Donington Park (GP layout). It's a great track and we had a wonderful day. There was also a couple of very unlikely coincidences (or we're living in the matrix, there was a segmentation violation and my private memory area spilled out into the general simulation).

We were there on a Friday, but the paddock was already filling up with cars that would be racing at the weekend. One of the races was "Mighty Minis" and we had great fun peering at the race-prepared classic minis. One of my more disparaging comments was "I don't think much of their fusebox". A circuit board full of fuse holders was screwed straight onto the shelf above the passenger's knees (if there were a passenger seat) with no cover or protection of any kind. About a minute later when we had walked back to my car, the glue on the back of the velco that holds my luxuriously appointed fusebox cover in place failed. The fusebox cover fell clanging into the passenger footwell. "I don't think much of your fusebox" said my friend.

During that same short walk across the paddock I overheard one of the mini racers say "He'll be here tonight, he's getting a lift up with Paul Inch". I said to my friend that that was someone else coming up from Plymouth. "How do you know he's from Plymouth?" "Paul Inch is an engine builder in Plymouth" "That's just a man's name, I bet there's more than one. He could be from anywhere". The next mini we passed had the bonnet open and a "Paul Inch" sticker was clearly visible on the rocker cover with an 01752 (Plymouth) telephone number.

At the same time, 150 miles away, the postman was delivering a Hillman Imp fanzine to my friend and both the racing cars on the front cover had "Paul Inch" header strips on their windscreens.

Richard "coincidence or something more?" B