Big Steam 2: Reciprocating Boogaloo
Just got back from the old Ann Arbor Railway depot here in Howell, where I watched Nickel Plate 765 pass through town en route to Owosso. I *could* have watched her from my bedroom window, but I decided to go out and get a better view from trackside, and I'm glad I did.
For whatever reason, be it liability, regulatory, or just the preference of the operators involved, 765, unlike SP 4449 on Sunday, was not leading the train; she moved from her home in Fort Wayne as a four-car (locomotive/tender, tool car, two deadhead passenger cars) freight shipment, delivered by Norfolk Southern to Milan, Michigan, where the current version of the Ann Arbor picked her up and took her to Ann Arbor, thence handing her off to my "backyard" road, the Great Lakes Central, to handle the rest of the way to Owosso. Being a freight shipment, she was considered "dead in tow" instead of providing power.
However, *no* steam locomotive ever truly moves dead in tow, because of all the moving parts in the valve gear that need constant lubrication whenever they're moving--and the lubricators are all steam-powered ones, requiring the locomotive to maintain at least 50 psi of steam pressure in the boiler at all times to operate them. Since the boiler is really designed for high-pressure operation instead of low-pressure operation, and the Federal Railway Administration counts it as a boiler operating day against the locomotive's maintenance schedule regardless of whether you fire her up to ten pounds or three hundred pounds, "dead in tow" steamers tend to be kept close to normal operating pressure, with just enough throttle applied to keep any condensation blown out of the cylinders.
Such was the case today... most of the time. See, just east of the depot, Michigan Avenue crosses over the tracks on an overpass, and unsurprisingly, a large number of people had congregated on the sidewalk there to watch the train pass, rather than wait at the depot. (As a point of reference, if you pan that map northwest about a mile up the tracks, you'll find my apartment complex bordering them on the west, inside the loop made by Greenwich Street.)
Now, having mentioned where these people were gathered, I'm sure that anyone familiar with steam locomotives is already laughing madly at what they know is coming, but for those who aren't, a quick bit of explanation is in order. Steam locomotives, particularly coal-fired ones like 765, tend to gather soot and cinders from their fires in their boiler tubes and superheaters. (Oil-fired ones like 4449 are less prone to this, as oil burns with less particulate products.) This debris tends to restrict the flow of the superheated combustion gases ("smoke") through the boiler, making it less efficient at boiling water and making steam.
To combat this, every so often--maybe once every few hundred miles if you're really working the engine hard, more often if you're just drifting along on a closed throttle--the fireman will "dust her flues out" by tossing a scoopful of fine, dry sand into the firebox, while the engineer opens the throttle all the way to get the maximum steam exhaust through the stack and maximum draft for the fire. The powerful draft over the fire will suck the sand out of the air before it can hit the fire, and suck it through the boiler tubes and superheater, then out the stack, carrying with it all the accumulated soot and cinders in the boiler, resulting in a volcanic eruption of oily, sooty black smoke from the stack, and a rain of soot and cinders onto everything in the general vicinity. (Since a steamer that's running efficiently will make a relatively small amount of whitish smoke, which becomes all but transparent when it mixes with the steam exhaust, this is often done at the request of photographers who want a dramatic smoke plume from the stack.)
I think you can guess what happened--seeing the people lined up on the bridge, the crew decided to give them a little something special, and just as they were at the right spot, they "dusted out her flues," resulting in the initial belch of smoke and crud just completely enveloping that overpass. Of course, she was still making plenty of black smoke and raining a lot of cinders when she passed the depot, but I was able to avoid the worst of the black rain by ducking under the overhang of the roof. (This did, however, leave me in a perfect spot to get absolutely deafened by 765's whistle as she went by!)
Next round of my Steam Overdose 2009 will be Saturday, when I go up with a bunch of the family to Train Festival in Owosso, the event that all this steam (eight locomotives will be present and simmering, the most in one place since Railfair '99 in Sacramento attracted 25 locomotives) is going to. The day will include chasing 1225 up towards Alma during her excursion of the weekend, among many other things... look for an update about it on Saturday or Sunday night!
For whatever reason, be it liability, regulatory, or just the preference of the operators involved, 765, unlike SP 4449 on Sunday, was not leading the train; she moved from her home in Fort Wayne as a four-car (locomotive/tender, tool car, two deadhead passenger cars) freight shipment, delivered by Norfolk Southern to Milan, Michigan, where the current version of the Ann Arbor picked her up and took her to Ann Arbor, thence handing her off to my "backyard" road, the Great Lakes Central, to handle the rest of the way to Owosso. Being a freight shipment, she was considered "dead in tow" instead of providing power.
However, *no* steam locomotive ever truly moves dead in tow, because of all the moving parts in the valve gear that need constant lubrication whenever they're moving--and the lubricators are all steam-powered ones, requiring the locomotive to maintain at least 50 psi of steam pressure in the boiler at all times to operate them. Since the boiler is really designed for high-pressure operation instead of low-pressure operation, and the Federal Railway Administration counts it as a boiler operating day against the locomotive's maintenance schedule regardless of whether you fire her up to ten pounds or three hundred pounds, "dead in tow" steamers tend to be kept close to normal operating pressure, with just enough throttle applied to keep any condensation blown out of the cylinders.
Such was the case today... most of the time. See, just east of the depot, Michigan Avenue crosses over the tracks on an overpass, and unsurprisingly, a large number of people had congregated on the sidewalk there to watch the train pass, rather than wait at the depot. (As a point of reference, if you pan that map northwest about a mile up the tracks, you'll find my apartment complex bordering them on the west, inside the loop made by Greenwich Street.)
Now, having mentioned where these people were gathered, I'm sure that anyone familiar with steam locomotives is already laughing madly at what they know is coming, but for those who aren't, a quick bit of explanation is in order. Steam locomotives, particularly coal-fired ones like 765, tend to gather soot and cinders from their fires in their boiler tubes and superheaters. (Oil-fired ones like 4449 are less prone to this, as oil burns with less particulate products.) This debris tends to restrict the flow of the superheated combustion gases ("smoke") through the boiler, making it less efficient at boiling water and making steam.
To combat this, every so often--maybe once every few hundred miles if you're really working the engine hard, more often if you're just drifting along on a closed throttle--the fireman will "dust her flues out" by tossing a scoopful of fine, dry sand into the firebox, while the engineer opens the throttle all the way to get the maximum steam exhaust through the stack and maximum draft for the fire. The powerful draft over the fire will suck the sand out of the air before it can hit the fire, and suck it through the boiler tubes and superheater, then out the stack, carrying with it all the accumulated soot and cinders in the boiler, resulting in a volcanic eruption of oily, sooty black smoke from the stack, and a rain of soot and cinders onto everything in the general vicinity. (Since a steamer that's running efficiently will make a relatively small amount of whitish smoke, which becomes all but transparent when it mixes with the steam exhaust, this is often done at the request of photographers who want a dramatic smoke plume from the stack.)
I think you can guess what happened--seeing the people lined up on the bridge, the crew decided to give them a little something special, and just as they were at the right spot, they "dusted out her flues," resulting in the initial belch of smoke and crud just completely enveloping that overpass. Of course, she was still making plenty of black smoke and raining a lot of cinders when she passed the depot, but I was able to avoid the worst of the black rain by ducking under the overhang of the roof. (This did, however, leave me in a perfect spot to get absolutely deafened by 765's whistle as she went by!)
Next round of my Steam Overdose 2009 will be Saturday, when I go up with a bunch of the family to Train Festival in Owosso, the event that all this steam (eight locomotives will be present and simmering, the most in one place since Railfair '99 in Sacramento attracted 25 locomotives) is going to. The day will include chasing 1225 up towards Alma during her excursion of the weekend, among many other things... look for an update about it on Saturday or Sunday night!