Sunday 25 March 2007

New York's District Heating

One of the images I had of New York was steam rising from manhole covers in the streets. Well, yes, it still happens.

Birdsill Holly (1820-1894) was an inventor who is credited with originating the concept of District Heating. He was born in New York State and the number of patents to his credit is second only to his friend Thomas Edison. By 1882 the Birdsill District Steam Heating System was in use in a number of cities across the United States.

Wallace C. Andrews set up a company to promote Birdsill's system in New York and in 1882 the first customers were supplied. The efficiency of the system lead to steady growth as the New York Steam Company and virtually all the famous buildings became customers. During the 1930s agreements were in place to exchange steam with gas and electric utilities to cope with peaks. In 1954, the steam business was acquired by Consolidated Edison.

Today, Con Edison Steam operates a network of 105 miles of mains and service pipes supplying around 1800 customers in Manhattan with steam for heating, hot water and air conditioning. See the Con Edison site.

Steam is distributed by underground steam mains rated at either 200 or 400 pounds per square inch. Periodic expansion joints and insulation are provided, together with a series of main valves operated manually from street level via manholes. There is no intentional release of steam at the surface - when this occurs it is due to leaks or surface water leaking into manholes and coming into contact with the hot steam main.

In various locations, I came across temporary chimneys erected over street manholes painted in white and orange stripes, presumably where maintenance work is taking place. The photograph above shows one such chimney on Fifth Avenue (with Central Park in the background). But can somebody explain the liquid nitrogen cylinders? I assume it has something to do with temporarily controlling leaks.

Sunday 18 March 2007

South African Railways

South African railways operates an extensive network of mainly 3 foot 6 inch gauge track. Some of the main lines and the commuter networks around Johannesburg and Cape Town are electrified. Electrification is overhead, using mainly 3kV d.c. with some 25kV a.c. and a small amount of dual voltage route.

I visited Johannesburg in February, 2007. I was unable to travel by rail but I did make some photographs showing the well-kept infrastructure and multiple-aspect colour light signalling. The main station at Johannesburg is large and complex - I was particularly interested in the diamond crossings with double slips. Because of the track gauge and the angle of the crossing, these are more complex than double slips on standard gauge, as the following picture illustrates:-

A few days later in Cape Town, I managed to make a journey one evening on the electrified suburban service to Bellville.

The first railway to be built in South Africa was the Cape Town - Wellington line, started in 1859 but not opened until 1863. The first locomotive is on display in Cape Town station. I managed one photograph before station staff decided that pictures of a 150-year old locomotive were a security risk! Click for my South African railway pictures.

Friday 9 March 2007

The New York Subway

Of course, on my first visit to New York, the challenge was to find out a little about the Subway and how it works.

The initial settlement in Manhatten is bounded by New York Harbour to the South, the Hudson River to the West and the East River. As New York grew, expansion occurred in the North, towards Harlem and beyond. The 1811 street plan set up the layout of North - South avenues and East - West streets which survives today. As it grew, New York became a victim of its own success and congestion on the North-South avenues made commuting horrendous.

The first improvement was the construction of elevated railways (illustrated below - a delightful diorama in the NYC Transit Museum in Brooklyn) which gave some relief. Many of the avenues were built over by the 'El' but, with short trains hauled by diminuitive Forney 0-4-4T steam locomotives, the improvement in conditions for the still-growing city was only temporary.

More elaborate plans envisaged underground electric railways speeding commuters in and out of the city and it's that system, opened in 1904, that's still in use, now with 25 lines and well over 400 stations.

In common with a lot of early underground railways, construction was mainly cut-and-cover, where existing roads are dug up to allow a railway to be built just under the surface and then the road is replaced on top. From the start, the principal routes were 4-track. Where space permitted, the two outer tracks were the 'Local' lines, provided with platforms at every station, whilst the 'Express' tracks only had platforms allowing interchange with the 'local' every so often. This approach was intended to minimise journey times. Where space was restricted, the 'local' lines ran near the surface, with easy access from the street, whilst the 'fast' tracks dived underneath the local lines.

Tracks are standard gauge and electrification is 625 volts d.c. using an outside third rail. The top of the rail is the pick-up area and a hinged skate on each bogie collects current. A horizontal wooden board is fixed above the conductor rail, presumably both for safety and to exclude ice and snow on the surface lines.

Each line is designated by a number or a letter. Trains which operate over only part of a line may have a separate designation. But with the perversity I imagine is typical of New Yorkers, the designation is applied to the train, not the line - for instance, (cue music) "If you take the 'A' Train". The front of each train carries the designation and all recorded announcements use the form "This is a Six Train for City Hall". Since many of the minor stations have their geographical position in the name, such as '51st Street', it's easier than I imagined to get to somewhere you've never been. There are also simple rules you can learn (I didn't on my short visit) to convert a building number into the nearest cross street, to decide where to get off.

In general, stations are busy and there are plenty of trains, although I did experience more than once a sudden hiatus where trains appeared to stop running for a while, followed by an equally mysterious resumption of service where the first train was crush-loaded. Most of the stations are fairly run-down and cramped in layout but they're reasonably lit, reasonably clean and I could see why residents make such use of the system.

Like the majority of subway systems, if you stand right at the front of the train, there's limited visibility ahead through the door to the driving cab, allowing the sharp deviations to be observed and giving at least a vague impression of some of the complex underground pointwork and the colour light signals.

Speed signalling appears to be in use so that a reduced speed indication allows the driver the anticipate the sudden lurch as the train is diverted from, say, the through line to the local line. As is common on this type of railway, approach release is used in places. For instance, running into a station a signal may remain red until a timer triggered by the occupation of track circuits clears the signal, provided the train's approach speed is consistent with stopping in the platform.

There's an interesting example of approach released signalling on the Manhattan Bridge, which carries four subway tracks, two used by B and D trains, two by N and Q trains. At the bridge approach, the trains pop out of the ground and climb a fairly steep gradient to reach the bridge deck, high above the East River. On the other side of the bridge, trains descend a similar gradient until they disappear back underground. As trains commence their descent, they're faced with at least half a dozen closely-spaced red signals. Provided the driver suitably regulates his speed, each signal in turn clears as the train approaches.

South Ferry is the terminus for One Trains, right by the Staten Island Ferry Terminal. This is currently a very antique station on a very tight curve, with a series of post and chain barriers to prevent you approaching the platform edge, except in the vicinity of the doors. It looked as if trains go round a dumb-bell to reverse.

The One Trains also seemed the most temperamental. Whilst all the trains come into stations fast and use quite heavy air braking to decelerate, they generally rolled to a stop at the correct point. But on a few occasions, One Trains braked heavily but stopped short with a jerk, necessitating drawing up before the doors opened.

I went out to Coney Island on a 'D' train. Once in Brooklyn, the line emerges to run on brick viaducts to Coney Island, four track most of the way. I returned by an alternative route which was also four-track and on the surface until the vicinity of Atlantic Avenue, Brooklyn.

The subway is operated by New York City Transit Authority. This is an agency of the Metropolitan Transportation Authority (MTA) which has operated New York's public transport since 1965. Other MTA-agencies run commuter rail lines, buses, bridges and tunnels. The Long Island Rail Road is owned by MTA and has nine lines radiating from New York into Suffolk and Nassau counties. Metro North Commuter Railroad is also MTA-owned covering the Harlem, Hudson and, in conjunction with the Connecticut Department of Transportation, New Haven lines. Lines to Port Jarvis and Pascack are operated in conjunction with New Jersey Transit.

The Staten Island Rapid Transit is another MTA agency. This is a surface line running the length of Staten Island (about 23km). Equipment is similar to the subway but the operating voltage was 600 volts d.c. Operation appears to be automatic except in the vicinity of the Northern terminus, by the ferry terminal, where signals are provided.

Click for my photographs of New York's Railways

[Expanded 18-Mar-2007]

Tuesday 6 March 2007

Two-train working at Peak Rail

Peak Rail inaugurated two-train working on Saturday, 3-Mar-2007 during their Mixed Traffic Weekend.

Jan was the driver of the steam-hauled passenger services using 'Austerity' tank locomotive 'Royal Pioneer'. Alternate passenger services were diesel-hauled.

The second train was a demonstration loose-coupled freight, hauled alternately by 'Royal Pioneer' or diesel traction.

The line from Matlock Riverside to Darley Dale forms one single line section, the line from Church Lane to Rowsley forms a second single line section. Trains pass on the double track between Darley Dale and Church Lane which is worked Absolute Block.

The first train of the day, 11:00 from Darley Dale to Matlock Riverside, was double headed by D8 (train engine) and 'Royal Pioneer' (pilot engine). On arrival at Matlock Riverside, 'Royal Pioneer' ran round the train, so that we were 'top and tail', with the steam locomotive leading on the way back. We were held briefly at the approach to Darley Dale, waiting for the demonstration freight to arrive in the Up platform before we could proceed. At present, Down trains are not stopping at Darley Dale. On arrival at Rowsley, the steam locomotive dropped off the train to take water and then stabled in the loop, leaving D8 to take the next Up passenger. The next arrival at Rowsley was the Class 31 with the freight. By this time, I'd been relieved by Gary Dixon, who coupled 'Royal Pioneer' onto the freight for its next run. This allowed me to travel on the brake van of the freight train and take some photographs. This pattern continued through the day until D8 coupled onto the last Southbound passenger at Rowsley with 'Royal Pioneer' as pilot for the short journey back to Darley Dale. Click here for photographs.

On the day, everything worked well and congratulations are due to everybody who worked to achieve this step forward for the railway. Note that, at present, two trains will only operate on certain dates.

Thursday 1 March 2007

No Place Like Home

Wednesday, 28-Feb-2007: Up at 5.00 am, check out of the Cape Grace, picked up by the young lady from CC Africa at 5.45 am, an easy journey to the airport. There's extensive building work going on so she has to drop me some way from the terminal and I have to go on foot with my luggage across a virtual building site to reach the terminal building. Good job I'm travelling (reasonably) light! Check in, through passport control and security and find the British Airways Terraces lounge. I'm amazed to find no internet access. There's a business section all wired up for computers, but no equipment. We are in a 'Wi-Fi' hot spot, but it's a chargeable one (as are most of them, except for some enlightened hotels) and it's too difficult to contemplate signing up for one session. Instead, I have a very light breakfast and try to relax before the fairly long flight (about 11.5 hours).

We board on time. The aircraft is a 747-400 and I'm on the upper deck. This is probably still my favourite aircraft, although this particular example is a bit long in the tooth and not all the features work properly, like some of the video channels. But the important bits seem OK and once the four massive turbofans are spooled up, they keep going without incident until we touch down at Heathrow Terminal 4. I get decent views of Cape Town as we take off, although I'm in an aisle seat, but I don't see much of the ground as we make our way North over the African continent. Our initial cruise is at 34,000 feet but, once we have burnt off some of our fuel load, we climb to 39,000 feet for the remainder of our journey. They serve a decent lunch soon after take-off then there's a long interval with snacks and drinks available on demand before they serve a decent dinner shortly before landing. Heavy winds around London mean we have to stooge around for about 15 minutes waiting to land, then we disembark and clear passport control quickly. Heathrow distinguishes itself by taking over 45 minutes to start disgorging the luggage (I've not had to wait for more than 10 - 15 minutes at any other airport on this trip), but at least my bag is one of the early ones. I meet up with Alan in the Arrivals Hall and he drives me home. I'm home at 10.15 pm to a wonderful welcome from my dog Tai, who has also been on holiday, staying with my friend Marion and her dogs Jack and Harry.

Thursday, 1-Mar-2007: It's wonderful to be home, with so many experiences to review and think about. As time permits, I'll probably ramble on further about some of the things I've seen. I've posted photographs in various Collections on my Flickr Site.

I know it's not the type of trip that would appeal to everyone (why stay such a short time everywhere? why so many trains?) but it works for me and I feel very fortunate that I'm able to undertake such a journey.