From article "Smoke Deflectors" by Herbert G. Monroe in Railroad Magazine Feb. 1941

Tunnels and Steam Locomotives

In earlier posts about our company name, CabForward℠, and how it was selected to represent how we like to do business, and origin of the term “cab forward,” I touched on the topic of smoke and exhaust from the locomotive being a source of problems for the crew (and passengers in cars behind the engine). Some of our research into the origin of the name led to interesting historical information.

Why Railroads Adopted Cab Forward

We traditionally think of the steam engine with the headlight and smoke stack in front of the cab, which is where the engineer and fireman worked. The engineer used the throttle and brake to control the train, while the fireman kept the fire burning and regulated the flow of water to the boiler to create the steam. The cab was located behind the boiler, which blocked their view to the front, so the engineer and fireman had to watch opposite sides of the track for problems or signals.

0-4-0 Loco with tender_sml

The steam engine (locomotive) pulled a tender, a special rail car which carried the water and coal which was used to generate the steam that powered it. Frequent stops were often necessary in order to replenish the water and coal supplies. The water supply was replenished from a dedicated water tower connected to water cranes or gantries. Refilling the tender is the job of the fireman, who maintains the locomotive’s fire, which uses the water supply to build steam pressure. The smoke stack was made tall enough that the smoke would usually be carried up high above the cab so the crew could work in fresh air. All bets were off, however, when the locomotive ran through a tunnel or snow shed, where the smoke and steam could get so thick it nearly suffocated the crew.

Steam Engine 587On railroads with lots of tunnels, or long tunnels, this posed serious problems. The smoke from the stack and steam from the exhaust would fill the cavity of the tunnel creating very difficult breathing conditions. The crew couldn’t get a breath of fresh air until the cab exited the other end of the tunnel. After a number of crews nearly asphyxiated or were seriously burned by the exhaust, steam engines were run in reverse to get the smoke stack behind the cab. This meant that the tender was leading the train, which introduced new problems. The could tender significantly block the view ahead, and put crewmen on the wrong side of the track for seeing signals. Also, tenders were not designed to be pushed ahead of the train, except at a slow pace, which seriously limited the speed of the trains.

Here’s an article, written in 1941, that describes what it’s like to be aboard a steam engine in a tunnel.

Smoke Deflectors

by Herbert G. Monroe
Railroad Magazine Feb. 1941

In 1902, This Rogers Consolidation was the Great Northern’s answer to smoke nuisance in the 3 1/2 mile Cascade Tunnel.

1902 Northern Pacific Rogers Consolidation

1902 Northern Pacific Rogers Consolidation

Ever since 1833, when construction engineers drove America’s first railway tunnel through a hillside four miles east of Johnstown, Pa., motive power men have cudgeled their brains for a solution to the difficult problem of smoke deflection. True, their first efforts were scattered and half-hearted, since early bores allowed worlds of atmospheric clearance for iron colts whose stacks reached high above slim boilers and gothic-windowed cabs. But there came a day when locomotives were to burst their brass belting and grow in girth until their stacks resembled nothing so much as warts on a Sequoia log.

Those of us who spent the period of transition in smoke-filled engine cabs will never forget the experience. When a big freight hog, with something less than a thousand loads at her tail, thundered into a tunnel and the dynamiting exhaust struck the ceiling like the muzzle-blast of a rapid-fire cannon, belching smoke was instantly deflected downward to enshroud us in a shriveling black fog. Somehow, we usually managed to weather through, but more than one good rail came out cooked like a Thanksgiving turkey.

Not only did the tunnels endanger the lives and health of engineer, foremen and head-shack, but very often the exhaust blasted key-bricks from the arched ceiling, thereby threatening to drop the mountains above straight through the open holes. It has been told how an engineer named Clancy – or maybe it was Moriarty – saved enough bricks on the “Rat Hole” run in a year to build a fine house. Most of them he took from the running board, but now and then one bounced through the window and clicked him on the cranium.

Back in 1907, when I was braking on the Southern, those falling bricks annoyed Master Mechanic W.H. Dooley, of the CNO&TP. Besides, he was tired of listening to the crews cuss. So it was that he went about building what might be termed the first “modern” smoke deflector. Unfortunately, Mr. Dooley soon found himself in the position of the man who built a cabin cruiser in his basement. He had the boiler makers in the Ferguson Shops at Somerset, Ky., cut out and fit an extension over the stack of one of the engines; an elbow pipe like the kind you’ll find behind a kitchen stove.

This member was about two feet high, and hinged in such a manner that it could be raised and lowered by a contrivance that included a set of gears and an air cylinder. Everybody gathered around to see the epic-making locomotive start off, and Mr. Dooley was as proud as a new father. The hogger cracked under the throttle, but he forgot to lower the smoke deflector and it knocked down part of the building. This was better than jarring the portal off a tunnel, for it was discovered that the device was too high to clear the main lines bores anyway.

Not disheartened, Mr. Dooley made another one. This was a right angle bonnet, or flop-over deflector. It was operated by a mechanism similar to the first, but, though the air was left on in the tunnel, the exhaust had a tendency to blast the bonnet off the stack. Dooley then cut off a third of the elbow, which allowed free passage of some of the exhaust until the deflected portion struck it, whereupon the entire exhaust was turned from the tunnel ceiling. The pressure at the top edge of the bonnet held it firmly against the stack. These bonnets are still used on some of the Southern’s engines, and a careful survey discloses that the original right-angle deflector, with minor changes, is a favorite on the Canadian Pacific, Great Northern, Santa Fe, the Milwaukee and several other top-ranking railroads.

As I have already stated, I was braking on the Southern about that time, on a run in the Atlanta-Chattanooga district. Athwart that route, just south of Braswell, Georgia, old Braswell Mountain stood glowering, plainly resentful of the snorting trains that rummaged around in her bowels. It was in this bore that I heard Gabriel trumpeting his call to man the Heavenly Express, on my first trip over the line.

The hogger and fireman had coaxed that hand-fired, saturated freight hauler up the grade with 1200 tons on her tail. When we hit the portal the steam pressure was down to 160 pounds. The tallowpot had been working his heart out, trying to wind her up against the pin, but the coal was tough, the fire was dirty and the old gal wasn’t what she used to be. Each long-drawn grunt threatened to prove her last. The added tonnage of a jay bird lighting on a box car would have stalled us. Every shovel of coal added to the density of the smoke belching from the stack. Just before we blasted underground, the hoghead eased the throttle off a few notches and dropped the Johnson bar down in the corner. Then he reached for the sander valves. Seeping water and exhaust evaporation would make the rails in the tunnel as slippery as a county fair greased pig.

Meanwhile, the foreman had gone to the gangway to gulp down a last breath of clean air. Already, we’d closed the windows and soaked big gobs of waste with water. The last trickle of daylight faded. The labored thunder of the exhaust slugged at our eardrums, the heat and the smoke grew ever more intense. It was like slow-baking in a Dutch oven. We buried our faces in our caps and the wet waste – coughing and choking. I had visions of stalling, and tried to steal a glimpse of the gage. I thought of the tank and wished I was in it to my neck – and then some. About that time the drivers started to dance, But the hogger caught her, like a wayward wench being dragged to her feet by a true Southern gentleman.

We were suffocating, and yet we burrowed deep in coats and jumpers, trying to shut out that stifling heat and smoke fumes. My ears rang – or, perhaps, it was chimes. I vowed that if I ever got out of Braswell Tunnel, I’d lead a sweeter, purer life. And then, suddenly, we were through, and Braswell Mountain was behind us.

Along in 1917, a pusher was located on Braswell Mountain. One day this engine was ordered to the shops. An engineer named Damon Hicks started up the hill with the ailing jack. When he entered the tunnel a cylinder packing was blowing. Before he got half way through it went out, enveloping him in a swirl of steam. To complete his discomfiture, the drivers started to spin and he couldn’t find the throttle for the ghostly “soup.” The pusher slipped down. Damon tried to start, but the old mill just danced. She was out of sand – the very life-blood of an engine in a tunnel. The other hogger had used it helping on the mountain during the night.

When Hicks finally got her out, and wiped his sweating face and hands with the waste he had to breathe in, every inch of skin came off. He was out of service several months, and still feels the effects of his experience under Braswell Mountain.

From article "Smoke Deflectors" by Herbert G. Monroe in Railroad Magazine Feb. 1941
Smoke hood used by the crew while traversing a tunnel. The host connected to the compressor, which delivered clean air into the hood. In order not to impede his movements, the Fireman’s hood is equipped with a longer air hose connected at the rear.

Biggest User of Cab-Forward Engines

Notably, the Southern Pacific Railroad adopted the cab forward design in 1910 to deal with the peculiar problems of its routes; 39 long tunnels and nearly 40 miles of snow sheds in the Sierra Nevada Mountains. The railroad converted from coal as a fuel to fuel oil, which allowed them to permanently move the tender to the “front” of the locomotive, and using low steam pressure from the boiler, could push the water and fuel oil to the cab. This allowed the locomotive to run “in reverse” with the tender and smoke stack trailing behind. The oil and water tanks were pressurized so that both would flow normally even on uphill grades. Visibility from the cab was superb, so that the engineer could easily survey both sides of the track.


The best known example of the cab-forward design in the United States is the Southern Pacific Railroad’s Cab-Forward AC-12 class engine 4294 which is on permanent display at the California State Railroad Museum. The design was widely used by the Southern Pacific Railroad, which eventually had a total of 256 Cab Forwards in various sizes. Southern Pacific initially commissioned Baldwin Locomotive Works to build a prototype cab-forward locomotive, then ordered 19 more before the prototype had even arrived.


How Cab-Forward Relates to Software Development

The railroads learned from their own experience, and innovated to overcome obstacles, such as getting trains safely through tunnels and snow sheds. We learned from waterfall project management in the past couple of decades that the system is flawed for contemporary software development, and innovation was needed to give our customers a better experience.

We adopted agile software development practices and lean process controls. Those practices are a very good fit for our philosophy and the way we want customers to feel about being in control of their project.

Whether the project is a mobile or web application, Ruby on Rails or other open source framework, the process is the same, and our objectives unchanged. We turned project management around, putting the client “up front” in the development cycle. That’s how the name CabForward℠ evolved. It imparts the overriding passion we have for providing the best customer experience available.

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