Other than a steam loco, nothing says “Old-Time Railroading” more than a wooden water tank—Part 2
By John B. Corns
Having completed a satisfactory design and size for a wooden water tank tub to hold the water destined for filling steam locomotive tenders and, eventually, steam locomotive boilers, the next aspect was to design an elevated tower to hold that tank of water high above the track. By pumping the water up into the tank only as needed to keep the tank full, the water would be immediately available at any time through a gravity-fed system that required only the efforts of the locomotive’s fireman to fill the tender.
Initially, water tank towers were made of wood, but through the years were sometimes replaced with stronger ironwork and even concrete. Timber towers were the most popular because the materials were inexpensive to purchase, easy to erect and simple to maintain. The American Railroad Engineering Association (AREA) standard water tank tower usually had 12 vertical posts arranged in two, intersecting rows of 8 posts each, forming an “X” when viewed from above. This 12-post tower provided a better distribution of the massive weight of the water above, and better supported the water tub’s bottom without the need for an elaborate floor system. The vertical posts were topped with horizontal 12”x14” timber caps upon which was built a framework of 4”x14” joists that supported the tub floor. To reduce rot and extend their service life, the vertical wooden timbers sat on concrete or stone pedestals called “piers” to keep the ends of the wooden posts out of the overflow water and accompanying mud that usually accumulated on the ground surrounding the base of the water tank. Each concrete pier had a 7-foot tall, 4’x4’ square-shaped base buried in the ground and topped with concrete shaped like a truncated pyramid.
Usually, the vertical wood posts were a minimum of 12”x12” square with a length as determined by the desired “head” of the water in the tank (its elevation and gravitational force) above track level. The AREA standard was 20 feet between the rail head and the floor of the tub, but that measurement varied from location to location, and even by the size of locomotive tenders. The twelve, White Oak, vertical posts holding up the Age of Steam Roundhouse Museum’s water tank are 17-feet tall, measure 14”x14” square, and are the most massive wood timbers in the entire museum complex. These posts have to be massive in order to support the 415,000 pounds of water contained in the roundhouse’s 16’x24’ 50,000-gallon wooden tub. As with the foundations of all structures at AoSRM, each of these 12 vertical posts and their concrete piers sits on a separate wood piling driven 25 feet down into the soft Blue Clay ground, using frictional support between the dirt and wood to hold all that weight. The water tank’s vertical posts are topped with 14” caps and 14” floor joists underneath the wooden tub, and combined with the height of the ground-level concrete piers, equals the standard 20-foot height above track level.
During the early days of railroading when locomotives and tenders were constantly being replaced with newer models having greater size and capacity, water tank towers had to be raised higher and higher to keep the water supply above the top of the tender. This was accomplished by installing larger blocks of cut stone underneath each vertical post in the water tank’s tower until the desired height above rail was achieved. (The Wheeling & Lake Erie used home-designed, cast iron pipes measuring 10’-6” tall as the legs for its water towers, but the road must not have considered that locomotive tenders would grow larger . . . and higher, so oftentimes several cut-stone blocks would be stacked underneath each vertical post to achieve the desired height. When tubs needed replacing due to deterioration, taller wood towers would be erected to prevent the jacking-up of too-short posts.)
To replenish the used water in the tank, delivery pipes extended from the ground into the bottom of the tub and were enclosed in an insulated, wooden “frost box” to prevent freezing. This box contained several layers of wooden walls covered with insulating felt or building paper, and which were separated by 2-inch air spaces. Five such insulating air spaces offered protection down to 30-degrees below zero (Fahrenheit) where the water consumption each 24 hours equaled the capacity of the tub. Put simply, the high amount of energy required to freeze fast-moving water causes it to still freeze at 32-degrees F, but at a slower rate than if the water were not moving. On railroads located in northern climates (particularly the Canadian Pacific), to prevent freezing it was not unusual to enclose the entire water tank and tower in a wooden structure equipped with a heating stove. As the Age of Steam Roundhouse’s 50,000-gallon water tank supplies water for a fire suppression sprinkler system, an electrically-powered immersion heater sits inside the tub to prevent the mostly stationary water from freezing.
All railroad watering facilities needed a nearby source to replenish the water as tanks were emptied. In larger cities the municipal water works was occasionally the supplier, particularly since the already-pressurized water did not need a railroad-supplied employee to operate the steam-powered pump to elevate the water up into the tub. A city meter was installed to record the amount of water that was consumed, and the railroad was billed accordingly. In rural areas, lakes and rivers were preferred as water sources with railroad pumphouses raising the water into the elevated lineside tanks. If an above-ground water source were not available, a well would be drilled to reach underground water. Depending on the terrain and its affect on the quality of the water source, a reservoir or settling pond would be constructed so that particulate matter—such as sand, mud and algae—could settle to the bottom of the pond so that clearer water toward the pond’s surface was pumped into the tank. These reservoirs and ponds were constructed to hold at least a week’s water supply to allow proper settling of particulates, thus reducing tub cleaning and locomotive boiler “blowdowns” that expelled water contaminated by foreign matter. An old railroad adage summed it up—“If you wouldn’t drink it, don’t put it into a locomotive.”
Adjacent to most water tanks sat a pumphouse containing a steam- or electrically-powered pump that raised water into the elevated tank. There were no set standards for these pumps and houses, so they were constructed from a variety of materials in a myriad of shapes, sizes and styles whose appearance varied from railroad to railroad. In some remote areas the pumphouse was incorporated as an integral part of a telegraph office or depot to reduce construction and maintenance costs. Some of the more interesting pumphouses had a wooden superstructure resembling an old oil derrick projecting through the roof, evidence of a water well drilled below the building.
While it was relatively inexpensive to construct and maintain, the wooden water tank had numerous drawbacks. Its flat tub bottom collected mud, sand and other sediments that could interfere with the water valve located in the middle of the tub’s floor. To clean out this accumulated mess, the tub would have to be completely drained so that a worker could descend the interior ladder to the floor and hand-shovel the mud into buckets. With the aid of a rope, a second workman removed the buckets through the roof hatch, and a third worker emptied the buckets into a standing gondola or dump truck for final removal. This was a very tedious and labor intensive process that needed repeating several times yearly depending on the quality and clarity of the water at that site.
High quality lumber in long lengths became scarce, adding to the wood water tank’s initial construction and maintenance costs. To save money, cheaper grades of lumber were substituted during initial construction, but in the long run this increased maintenance and costs. Deferred maintenance increased the number of wooden water tank failures, so, as their budgets allowed, railroads began installing steel water tanks on a trial basis.
Steel water tanks had been around for many years, but were rejected at first because of their higher costs of materials and construction, leaky riveted seams, susceptibility to corrosion and increased maintenance. Most small railroads rejected the idea of steel water tanks because of their high initial cost, but larger, more profitable roads recognized their superior qualities—especially over a long period of time—and adopted them, if possible. Steel water tanks were installed at busy locomotive terminals where huge storage capacity was required, thus offsetting the cost of having several smaller wood water tanks to do the same job. Steel tanks maintained higher water temperatures during winter weather because of their insulating false-bottoms and tight-fitting steel roofs. The conical- and hemispherical-shaped bottoms of steel water tanks also permitted easier and more economical, one-man removal of sediment and sludge by flushing them out through a drain valve on the side of the conical bottom without having to empty the entire tank, or needing three workmen to do the same job. Steel tanks were stronger than those of wood, had greater capacity, were easier to clean, and needed less maintenance, that is, after several problems had been solved with the design of early-day steel water tanks.