Saturday, 2 September 2017

Nan & Pop - My Maternal Grandparents

I was just 4 when my mother's father died, and about 12 when her mother followed. My memories of them are strictly of the childhood kind, odd snippets, out of context.

They did not have a happy or fortunate life. Before the War, they lived in a series of tenements in south London. My mother remembers one of them that was next to a tripe yard, where lorries piled up high with raw tripe would arrive from the slaughterhouse to be distributed to the nearby butchers. Even a small piece of the stuff stinks, the stench from truckloads of it must be beyond imagination. We ate all kinds of offal when I was small - liver, kidneys, heart - but my mother could never bear tripe and we never ate it. Earlier they lived for a long while in the Borough, just south of the Thames. That was where my mother spent her infancy. It was not a nice place in those days.

Holding their first grandchild - they
must be in their late 50s 
My grandfather was universally known as Pop. He grew up in a small village in the depths of the Suffolk countryside - Glemsford, of which more later. Like so many of his generation, he fought in the trenches in WWI, and he survived it. What made him come to London in search of fortune, I'll never know. I remember one photo of him, a tiny contact print. He had a moustache - even though I was only 4, I can remember him tickling me with it. He worked in a bakery as a general labourer. One of his jobs was cleaning the huge ovens - this was done as soon and as quickly as possible, meaning he had to climb inside them when they were still hot enough to cook you if you lingered.

My grandmother was not - to be very kind - the easiest person to get along with. Her life wasn't easy, either. She had a deformity that made one of her legs several inches shorter than the other, and wore surgical boots all her life which must have been a miserable experience. In those days people like her weren't physically handicapped, or disadvantaged, or differently abled - they were cripples, with all the contempt and disdain that one short word onomatopeically captures. I know that she was born in Gravesend, Kent, but I have no idea how she ended up in London. In those days working-class women didn't have jobs, but that doesn't mean they didn't work. In addition to raising three children and keeping house before there were any machines to help, she took in washing, cleaned offices, and all the other miserably paid menial jobs that were open to her kind. I'm sorry to say that the daily unhappiness of her life reflected in her personality. She was never happy with anything and could always find a reason to complain, in complete contrast to Pop who - by all accounts - could always see the cheerful side of anything.

Pop's WWI campaign medals
Pop had been admitted to hospital for something, not serious. At visiting time, a nurse came by and he asked for a cup of tea. She turned her back to pour it, and when she turned back he was dead. Nobody could wish for a simpler, easier way to go. He was around 70, I'm not sure anyone knew his exact age.

My grandmother wasn't alone after his death. She shared a large house in Brixton, south London with her other daughter - my aunt - and her husband and two children, my cousins. There were four large rooms upstairs and four downstairs, where my grandmother lived. There was no bathroom, and no inside toilet - though at least the toilet was only just outside the back door, unlike my other grandmother's house in Dovercourt where it was at the bottom of the garden. After Pop's death, they converted one of the downstairs rooms into a bathroom. Until then, weekly ablutions were in a tin bath, filled from the kettle. Yes, really.

The house became briefly famous several years after her death, when my aunt's family had moved on. 22 Normandy Road was the epicentre of a riot in Brixton when police shot an innocent woman, whose home it had become by then.

After Pop's death she would go on holiday every summer, in Southend. It's a short train ride from London, a classic English seaside town. Its main claim to fame is the longest pier in Britain, at 1¼ miles - it even has its own train. I went there often as a child, though never for more than a single day. My grandmother went for a week, no doubt a memory of one-day "holidays" there before the War. She always stayed in the same bed-and-breakfast, a brisk walk back from the seafront. During the day she would sit in a promenade shelter along with the other old folk, watching the grey Thames estuary. Lunch was always at the Black Cat Café. I've never been there, but it's easy to imagine the greasy sausages served with hot, sweet, milky tea.

One thing she did enjoy was a game of cards - not that it stopped her complaining that the pack wasn't fair, that she was on a losing streak, and everything else you can imagine. From an early age I was introduced to the game of seven-card brag. Unlike the three-card variant, this isn't a gamblers' game, more something for a family evening round the fire. Pop had a fantastic memory for cards. He could remember every card that been played, and who played them when. In brag the cards aren't shuffled between games, so remembering the cards is a huge advantage.

My last memories of her are of visiting her in the Camberwell hospital where she died. Hospitals are never happy places, and Victorian hospitals in the 1960s were miserable even by those standards. I remember hanging around by her bedside while the adults tried to think of something to talk about.

During the War there was a major effort to move children out of London and into the countryside, where there was less risk of being bombed. Of the risks of abuse of all kinds, we won't speak. Mostly children were sent on their own, their parents staying in London to work. It must have been traumatic and awful, for most of them anyway. My grandmother chose to go there herself, taking my mother and her sister to Pop's family in Glemsford. She hated it there. The contrast between the primitive bucolic quiet and the bustle and filth of London is hard to imagine nowadays. They stayed for just two weeks before scurrying back to The Smoke.

But several years after her death, when I was a teenager, we drove one Sunday to Glemsford, our family piled into the load space of my Dad's delivery van. My mother remembered the house, and as we stood outside looking at it, a kindly lady came out and invited us in for tea - a last link with my barely remembered grandfather.

Wednesday, 7 June 2017

Railroads to the Gold

For someone raised in Europe, the sheer scale of the American West is hard to grasp. It takes a long day of driving to get from San Francisco to Las Vegas. But when you finally arrive, after 10 hours or more on the road, you are still only about a third of the way to the Rockies. To cross Nevada on US Route 50 will take all day, if you stop from time to time, and you will pass through almost nowhere, just endless desert and mountain ranges. Not for nothing is it called "the loneliest highway".

But it was the railroads that made the West, not roads. The first transcontinental railroad connected California to the then edge of civilisation at the Mississippi, nearly 2000 miles away. It was built in the astonishingly short time of 6 years, crossing the vast deserts of Utah and Nevada, the Rocky Mountains and even more challenging Sierra Nevada. Apart from the vast hostile terrain, its builders also had to deal with the understandably hostile natives, who would see their homelands torn away from them as a consequence.

The first main lines in Britain were the London and Birmingham and the Great Western, from London to Bristol. These were both a bit less than 100 miles long, nothing at all compared to what was needed in the US. Once the trunk lines were built, in both countries, there was the opportunity to build branches to serve other towns. A typical British branch line was 10 or 20 miles long. It would carry a daily goods train, stopping at every station to set down and pick up wagons, and a handful of daily passenger trains, also stopping at every station.

There were branch lines in the West too, but they ran to hundreds of miles. In 1905, gold was discovered in a truly middle of nowhere place, soon named as Bullfrog, about half way between Las Vegas (which itself barely existed at that time) and Reno. Very quickly the towns of Rhyolite and Beatty were established.

Immediately there was a need for railway connection to this new bonanza. And so not just one, but three separate lines set out across hundreds of miles of desert to reap these new-found riches. One, the Tonopah and Goldfield, came from the north. From the south two completely separate lines were started, built by rival organizations: the Tonopah and Tidewater, heading due south across arid desert for two hundred miles, and the Las Vegas and Tonopah, starting from a junction with the Union Pacific at Las Vegas. They were originally supposed to be a single line, but their founders had a serious disagreement and each decided to build their own line.

Building these lines across the desert was a massive undertaking. They ran on the eastern fringes of Death Valley, the hottest place in the world where summer temperatures routinely exceed 50°C. The men worked in gangs, one digging while all the others threw cold water - a precious and expensive resource itself - over him and each other. No reasonable person would try and work in the summer heat of the desert - but there was money to be made, every day the railway wasn't built was revenue lost.

But gold mines are fickle things. The Bullfrog deposits gave generously but were quickly exhausted. By the time the railroads had been built across the desert, a total of 500 miles (25% further than from London to Edinburgh) the mines were played out. Already the population of Rhyolite had fallen drastically, from 5,000 to around 1,500. When people moved out they took their houses with them - they were simple wood structures, easily reduced to planks and nails, and wood was expensive.

The railway station, though was a much more permanent edifice. In fact even now, after a century of neglect and abandonment, it is still standing, the only intact building in the much-visited ghost town of Rhyolite.

On lines this long, train services were much less frequent than on Europe's shorter branches. There would be at most one daily passenger train, taking all day (or all night) to cover the 200 miles of track. As services ran down, reflecting the reality that there was really no traffic left, the services was reduced to every two or three days.

In summary, by the time the railway got to Rhyolite, there was nothing for them to do - "all steamed up and nowhere to go".

Rhyolite Depot, still standing in 2017
As you'd expect, the two southerly lines were quickly rationalised. The Las Vegas and Tonopah stopped running trains in 1919, after just 11 years. It had never made sense for there to be two lines, even if Rhyolite had prospered for much longer.

In Britain it wasn't unknown for railways to be duplicated for purely competitive reasons, just not on this scale. The tiny town of Ramsey, Cambridgeshire (population 5000) had two lines that met head on, one built to stop the other invading its territory. But each line was only about 10 miles long, not 200.

The Tonopah and Tidewater scraped a living shipping borax from the quarries around Death Valley. It also tried to become a tourist line, feeding the 1920s Furnace Creek Inn in the valle via the narrow-gauge Death Valley Railroad. It never fulfilled the promise of its name - Tonopah was 100 miles north of the Rhyolite terminus, while the closest it got to tidewater was at Ludlow, in the middle of the Mojave desert 200 miles from the sea. Somehow the line struggled on through the 1930s, despite major flood damage in 1933 and 1938. It finally closed in 1942, and now it's very hard to find any trace of it.

The Tonopah and Goldfield hung on for a bit longer, not closing until 1947. It scraped a living serving the ranchers and the small remaining mining activity in the desolate area between Beatty and Tonopah. Many of the ties (sleepers) were sold to Scotty's Castle for use as firewood, where they remain in a huge pile.

Today it's the first line to close, the Las Vegas & Tonopah, that is the easiest to find, since most of highway 395 from Las Vegas to Beatty follows its path.

It seems incredible that 500 miles of railway would be built, in the amazingly short time of just three years across uninhabited, desolate country, to serve a single collection of mines. And sad that despite that, the mines were already running down by the time they got there, leaving them to eke out an existence serving a population that barely existed.

Sunday, 30 April 2017

What Does "The" Mean?

It's a word we use a thousand times a day, but trying to pin down its meaning turns out to be really quite hard. What does "the" mean? What is the difference between "the house", "a house" and just "house"?

To a native speaker of English, or another language that has the equivalent word (like French or German), it's so intuitive that it will seem like a silly question. But for speakers of languages that don't have it, like Russian, it's a mystery. It's very characteristic of native Russian speakers to speak and write without articles, like "Where is station?"

(There's an old joke about a Russian who arrives in England at Victoria station (I said it was old) and realises his watch has stopped. He approaches someone, who just happens to be a professor of philosophy, and asks, "Excuse me please, what is time?" To which the answer is, "That, my friend, is a very difficult question.")

A little thought shows that "the" somehow ties the noun in question to some mutually shared context. More than that depends entirely on the context in question. One of the harder questions in computational linguistics (and there are plenty of them) is to figure out the referent (what is being talked about) when "the" is used.

If I say to my partner "where is the car?" it is implicit that I means our shared car, or the car we happen to be using at the moment. But if I say "I saw a bad accident yesterday, with a car and a bus. The car rolled over",  it means a car we've never talked about before, one I introduced in the previous sentence. I can even introduce a previously-unknown referent with "the". It's a common turn of phrase to say something like, "The car that parked in my space yesterday was back again today." It's really a shorthand for "There was a car that parked in my space yesterday, and it was back again today."

If I walk up to a stranger in the street and say "Where is the car?" they will just be puzzled, because they have no context to identify any specific car. But if I ask "Where is the station?", they will apply common sense to assume I mean the station in the town we happen to be in, or the nearest station.

"A", by contrast, implies something that is brand new to our discourse. "I bought a hat yesterday" means some hat that we've never spoken of before, at least when uttered all by itself. (It could be followed by, "Remember, the green one we saw last week", which changes the meaning completely).

Many, probably most, languages get along just fine without being able to make this distinction. Japanese has an interesting variation, the so-called "topic marker" (は, pronounced "wa"). This is generally considered to be very difficult for foreigners to get the hang of, yet if you think of it as "the" you will get along just fine. It is in opposition to the "subject marker" (が, pronounced "ga") which is somewhat equivalent to "a". If I say "car-wa has broken down", it means (in the absence of some other context) "my car" or "our car". But if I say "car-ga has broken down" it means "some other car, that we didn't know about before", maybe to explain a traffic jam - which particular car is unimportant. (Like everything in language it's more complicated than this, but it's a good enough explanation to get by with).

The thing that suddenly made me think about all this was something I wrote recently. There is another meaning of "the" where the referent is the notion of the thing, rather than the thing itself. If I say "The car has changed the way people live", it's obvious I'm not referring to any particular car, but rather the idea of the car, car-ness in general. We use this meaning without even realising it, yet it is completely different.

I wrote a blog article called "The Five Pound Note". It started out as a general discourse on British currency in general, and the banknote worth £5 in particular. But then I told the story of one £5 note in particular, that dropped from my mother's purse while we were boarding a bus when I was a child. In other words, I had switched the meaning of "the" in mid-article. This use of "the X" to mean (roughly) "some X which you'll find out about if you read this" is very common in literary titles: The Very Hungry Caterpillar, The Mouse That Roared, The Sting.

All of which is one small part of why computers have a long way to go yet before they can really figure out natural languages that humans use all the time without even thinking about what they are trying to say.

Monday, 10 April 2017

The Five Pound Note

I'm just preparing for a trip back to the UK. As usual I'm assembling a little bag of UK banknotes and change,  but this time I'm being a bit more careful since the current one-pound coin and five-pound note are about to be withdrawn and replaced.

The one pound coin was introduced in 1983 - until then we had the pound note, which (unlike any modern British notes) was green. And before decimalisation in 1972, there was even a note for half of one pound, the 'ten bob note' (ten shillings, 50p in modern money). It was a little smaller than the pound note, and a reddish-brown colour.

The ten-bob note still lives on, in the colloquial expression, "bent as a nine-bob note" - meaning dishonest or corrupt. "I wouldn't buy nuffin' from that lot, they're all bent as a nine-bob note". Because a nine-shilling note would necessarily be a forgery. And also it alliterates nicely.

Five pounds used to be serious money, at least for a working class family like mine, as I once saw very vivdly. I must have been about seven or eight. We were on our annual week's holiday with my grandmother in Dovercourt, close to the ancient (and still very important) port of Harwich. She'd retired to a tiny cottage there around the time I was born. It was just big enough for her, my parents and myself, my parents sleeping on what must have been a horribly uncomfortable convertible sofa (a "put-u-up") that had to be unfolded after dinner every night and restored to its daytime function every morning. To a small child it was a paradise. The beach, with its choc-ices and endless civil engineering possibilities, was short bus-ride away on the exotic green Eastern National bus. There was a ferry across the estuary to Felixstowe, with its fairground, and walks along the promenade to see the long-disused lighthouses.

We had just got off one of those green buses, on our way to the beach, when my mother gave a gasp of horror. One of those five pound notes was missing from her purse. She was sure she'd had it when we left, so it must have come out somehow during the journey. That single banknote represented most of our holiday budget. My father earned about £30 per week, as a shop assistant selling the odds and ends that went into the then-thriving East End clothing industry along with the fabric itself.

My mother wasn't given to tearful outbursts, and I don't remember her crying, but it was certainly a very stressful moment. I remember her doing the mental arithmetic to see what kind of holiday we could still have on the remaining money in her purse. She tried to reassure me that everything would be alright, but I don't think it would have been.

In desperation, she made a phone call to the bus depot which occupied a very central position on Dovercourt's main shopping street. And, miracle of miracles, someone had seen the note fall and given it to the driver, who had handed it in to the depot as he drive past. I think maybe my mother did cry then. I won't say "that would never happen today", because I think these random acts of kindness are still common enough, and people were no more honest then than they are now. But certainly it was a huge stroke of good luck.

And there was better to come. My mother jumped on the next bus into town and rushed into the garage. The rule was that the bus company took 10% of the value of any lost property, as a way to cover their costs in handling it. Getting 90% of our holiday budget back was a lot better than losing it all, but it was still a significant dent.

The man in the bus garage office said to her, "Well, rightly we ought to take ten shillings off you. But you called almost before it was handed in, so it don't seem right really." And gave her back her whole five pound note, without taking the 10% they were entitled to. Really I'm sure he just felt sorry for my  mother.

So our holiday proceeded with its intended budget after all. The fact that I still remember all these details - I can even remember where we were and what kind of bus it was (a Bristol MW or LS single decker, since you didn't ask) - speaks volumes about the impact this little incident had on a small boy at the time.

Saturday, 4 February 2017

The Unstoppable Mr Bouncy - an LGB Track Cleaner That Works

When I started to put together my LGB garden railway, I quickly realized I would need some way to keep the track clean. The brass rails oxidize quickly outdoors, not to mention getting covered in bits of leaf and general garden dirt. Clean track with a bright, conductive surface is essential for smooth operation.

It’s possible to clean track by hand, of course. I have about 100 feet of track - small by garden standards - and it is a thoroughly unpleasant and back-breaking job, shuffling around the garden on your bottom, scratching away at a couple of feet of track at a time. There has to be a better way.

LGB have thought of this, and they give you two possibilities. One is a goods wagon with a couple of tiny abrasive pads on the bottom. Experience with even a small, indoor layout shows that these quickly wear out and get clogged. The Rolls-Royce alternative is the Track Cleaning Loco, styled after the yellow track maintenance vehicles you see all over the world. At least, originally they were yellow. When they introduced a DCC version, it became red.

I found a used yellow one, pre-DCC, on Ebay. With the installation of my usual NCE decoder, it was good to go. It would trundle around the layout, its cleaning wheels grinding away and leaving fresh, shiny track behind it. Perfect. At least, for a couple of feet. Then it would stop - because the track was dirty. It has a very short wheelbase, so it only takes slightly uneven track plus a bit of dirt for it to be deprived of power. This is a problem for all locomotives, but for one whose job is to take care of dirty track it completely defeats the objective.

As shipped, there is no control to turn on and off the cleaning motor. If you drive the loco forwards, it cleans as it goes, making a terrible noise that sends our cat scrambling for the fence. In reverse, it runs quietly and without cleaning the track. Neat, but not always convenient.

Early in its life, it had a disaster. While I was tinkering with it, body removed, a loose wire touched the track, shorting the track power to the motor. This fried not only the decoder, but also the LGB board that runs the lights and so on, and even some of the external electrics of the layout itself. I took advantage of that to do a full DCC installation, using a cheap Chinese voltage step-down board to supply an adjustable voltage to the cleaning motor. This could now be controlled using DCC with a relay to switch the power to it. It pulls about 2 amps, way beyond the auxiliary output of the decoder.

It was operable again, but still needed clean track to work. It bounces along the track quite violently as the cleaning wheels oscillate against its movement, so much so that we christened it Mr Bouncy.

The first year that I reopened the layout in spring, I had no choice but to clean the whole layout by hand. It really is a miserable job, and it persuaded me to try and make Mr Bouncy actually work.

My first attempt was to fit NCE's own booster module. This uses six one-farad supercaps in series. Supercaps are amazing things. Until about 10 years ago, the largest capacitor you could get was about 100,000µF. And it was huge. Supercaps use a different technology making tens end even hundreds of farads perfectly practical. The only problem is that they run at very low voltages - normally 2.7V. The NCE booster turned out to be useless - it can only run at 15V, so I had to turn down my 18V track voltage. That upset several of the locomotives, and made smooth running much harder. And it just didn't have enough capacity for a loco as large as this. - in fact it had no effect at all.

Nevertheless, supercaps are a very attractive solution to the problem. I thought about various ways to use them. I bought a bag of 10 30F units, and just for the sheer ridiculousness of it, a 350F supercap, which is about the size of a D-cell battery. Unlike a battery, though, it will cheerfully supply tens or even hundreds of amps for as long as it is charged.

The problem is that supercaps have to be carefully managed. You can connect them in series, but even so you have to to do something to ensure that none of them go over the individual voltage limit. You also have to control the charging current - a discharged supercap will cheerfully pull hundreds of amps. That looks like a short circuit to the rest of the layout, and will just shut down the power supply. There's a very nice chip (the LTC3350) made to deal with exactly these problems, but it's not suitable for the kind of amateur construction I'm doing. For one thing it's only available in a PQFN package, which requires industrial machinery to solder.

So I tried a different approach. I bought an LGB crane wagon on Ebay, and fitted it with metal wheels and a connector to feed the loco. I figured that the extra wheels and longer wheelbase would allow it to find a way through dirty track. It helped a little, but not much. The cleaner would still not go round the layout, even when the track was in reasonable shape, without constant attention and the occasional prod.

So it was back to the supercap solution. There are two problems: how to reduce the track voltage to something acceptable to the supercap, at the same time controlling the charging current; and how to bring that voltage back up to the 18V or so that the decoder is expecting.

Electronics, Ebay, and cheap Chinese modules to the rescue this time. There are switch-mode power supply chips that do these jobs, and better yet, you can buy them assembled into modules for under $5. My solution used two of them: one, a buck converter, to reduce the track voltage to 5.2V to feed two 30F supercaps in series, with a constant current mode allowing the charging current to be controlled to 2A. They're in series because the boost converter, that turns 5.2V back into 17V supposedly requires 5V to operate. In reality it works fine down to 3V, but not 2.7V. The two of them fit side by side on a board along with the two supercaps and a few other components, and the whole assembly just fits into the available space in the front part of the loco, above the cleaning wheels and motor. A clever design would allow the two converters to be combined, using a single inductor - that's precisely what the LTC3350 does. But it would have taken a lot more of my time than just soldering a couple of modules to a board.

The extra parts are quickly explained. The two big diodes on the left are 1N5422 5A Schottky diodes. They feed the higher of the input voltage and the output of the converter, to the output. The converter is set to slightly less than the track voltage, so its output is only used when the track voltage is absent. The smaller 1N4001 beside them ensures there is no reverse current through the step-down converter. The LED and zener at the top right show when the supercaps are charged close to 5.2V. There is a second supercap under the board, fitting into the gap between the wheels.

One modification is required to the decoder, which isn't designed to work with a booster like this. The power input circuit, consisting of a bridge rectifier and a smoothing cap, needs to be separated from the rest. Luckily, in the case of my usual NCE decoder, this can be done by cutting just one track, and soldering wires either side of the cut to connect to the booster. First the heatsink must be removed from the base, by cutting the shrink-wrap that holds it in place. The picture also shows one of the extra wires soldered on. Once the modification has been made and tested, the heatsink is replaced and held in place with a new piece of one-inch shrink wrap.

Finally it was time to test Mr Bouncy on the track. And this time, he worked perfectly. The track was filthy, unused for several months and black with oxide. I cleaned a short stretch, put Mr Bouncy on it and left him to charge - it takes about 30 seconds for the supercaps to charge fully. Then I set him slowly in motion. It was a pleasure to watch. The cleaner motor runs only on track power, so you can easily hear when power is interrupted. But the traction motor uses the booster. He will continue to trundle along slowly for up to about ten seconds, invariably enough to reach good power again and recharge. At first the cleaner runs only very intermittently, but on the second pass the track is a little cleaner and by the fifth pass it was running almost continuously, leaving beautiful shiny rails behind himself. A handful of times he did stop altogether, but the small current available through the dirty rails was enough to slowly recharge the supercaps, until he nudged along a few inches and then reached good power again. He can just be left to make a dozen or so circuits of the whole track, without any supervision at all.

We're very close to perfection now. One remaining problem with Mr Bouncy is that the rails aren't cleaned evenly. For some reason a little oxide remains over the sleepers, but not in between them. Clearly the height of the railtop is not exactly constant. I think the solution to that is to attach a conventional "scraper" type rail cleaner behind him, to finish the job off, and I've just ordered one of those. It is a real pleasure to watch him going round and round, occasionally idling along under his own power but never coming to a stop. And much easier than doing the job by hand. Though our cat, Missy, doesn't really agree.