It is an Ashcroft gauge having a handsome 4--4--0 locomotive engraved on its silver face.
The steam jet (item 3, fig. 18) is one of the simplest yet most notable boiler fitting of the _Pioneer_, being nothing more than a valve tapped into the base of the steam dome with a line running under the boiler jacket to the smokestack. When the valve is opened a jet of steam goes up the stack, creating a draft useful for starting the fire or enlivening it as necessary. This device was the invention of Alba F.
Smith in 1852, according to the eminent 19th-century technical writer and engineer Zerah Colburn.[15]
The two feedwater pumps (fig. 20) are located beneath the cab deck (1, fig. 17). They are cast-iron construction and are driven by an eccentric on the driving-wheel axle (fig. 27). The airchamber or dome (1, fig. 27) imparts a more steady flow of the water to the boiler by equalizing the surges of water from the reciprocating pump plunger. A steam line (3, fig. 18), which heats the pump and prevents freezing in cold weather, is regulated by a valve in the cab (figs. 18, 27). Note that the line on the right side of the cab has been disconnected and plugged.
The eccentric drive for the pumps is unusual, and the author knows of no other American locomotive so equipped. Eastwick and Harrison, it is true, favored an eccentric drive for feed pumps, but they mounted the eccentric on the crankpin of the rear driving wheel and thus produced in effect a half-stroke pump. This was not an unusual arrangement, though a small crank was usually employed in place of the eccentric. The full-stroke crosshead pump with which the _Jenny Lind_ (fig. 22) is equipped, was of course the most common style of feed pump used in this country in the 19th century.
[Ill.u.s.tration: Figure 19.--BACKHEAD of the _Pioneer_. (Smithsonian photo 48069F.)]
Of all the mechanisms on a 19th-century locomotive, the feed pump was the most troublesome. If an engineer could think of nothing else to complain about, he could usually call attention to a defective pump and not be found a liar. Because of this, injectors were adopted after their introduction in 1860. It is surprising that the _Pioneer_, which was in regular service as late as 1880 and has been under steam many times since for numerous exhibitions, was never fitted with one of these devices. Because its stroke is short and the plunger is in less rapid motion, the present eccentric arrangement is more complex but less p.r.o.ne to disorder than the simpler but faster crosshead pump.
[Ill.u.s.tration: Figure 20.--FEEDWATER PUMP of the _Pioneer_. (Smithsonian photo 63344.)]
The check valves are placed slightly below the centerline of the boiler (fig. 18). These valves are an unfinished bronze casting and appear to be of a recent pattern, probably dating from the 1901 renovation. At the time the engine was built, it was usual to house these valves in an ornamental spun-bra.s.s casing. The smokestack is of the bonnet type commonly used on wood-burning locomotives in this country between about 1845 and 1870. The exhaust steam from the cylinders is directed up the straight stack (shown in phantom in fig. 27) by the blast pipe. This creates a partial vacuum in the smokebox that draws the fire, gases, ash, and smoke through the boiler tubes from the firebox. The force of the exhausting steam blows them out the stack. At the top of the straight stack is a deflecting cone which slows the velocity of the exhaust and changes its direction causing it to go down into the funnel-shaped outer casing of the stack. Here, the heavy embers and cinders are collected and prevented from directly discharging into the countryside as dangerous firebrands. Wire netting is stretched overtop of the deflecting cone to catch the lighter, more volatile embers which may defy the action of the cone. The term "bonnet stack" results from the fact that this netting is similar in shape to a lady"s bonnet. The cinders thus acc.u.mulated in the stack"s hopper could be emptied by opening a plug at the base of the stack.
While the deflecting cone was regarded highly as a spark arrester and used practically to the exclusion of any other arrangement, it had the basic defect of keeping the smoke low and close to the train. This was a great nuisance to pa.s.sengers, as the low trailing smoke blew into the cars. If the exhaust had been allowed to blast straight out the stack high into the air, most of the sparks would have burned out before touching the ground.
[Ill.u.s.tration: Figure 21.--"PIONEER" ON EXHIBIT in old Arts and Industries building of the Smithsonian Inst.i.tution. In this view can be seen the bonnet screen of the stack and arrangement of the boiler-frame braces and other details not visible from the floor. (Smithsonian photo 48069A.)]
[Ill.u.s.tration: Figure 22.--"JENNY LIND," SISTER ENGINE of the _Pioneer_, shown here as rebuilt in 1878 for use as an inspection engine. It was sc.r.a.pped in March 1905. (_Photo courtesy of E. P. Alexander._)]
[Ill.u.s.tration: Figure 23.--CYLINDER head with valve box removed.]
[Ill.u.s.tration: Figure 24.--BOTTOM of valve box with slide valve removed.]
[Ill.u.s.tration: Figures 25 and 26.--CYLINDER with valve box removed, showing valve face.]
FRAME
The frame of the _Pioneer_ defies an exact cla.s.sification but it more closely resembles the riveted- or sandwich-type frame than any other (figs. 18, 27). While the simple bar frame enjoyed the greatest popularity in the last century, riveted frames were widely used in this country, particularly by the New England builders between about 1840 and 1860. The riveted frame was fabricated from two plates of iron, about 5/8-inch thick, cut to the shape of the top rail and the pedestal. A bar about 2 inches square was riveted between the two plates. A careful study of photographs of Hinkley and other New England-built engines of the period will reveal this style of construction. The frame of the _Pioneer_ differs from the usual riveted frame in that the top rail is 1-3/4 inches thick by 4-1/8 inches deep and runs the length of the locomotive. The pedestals are made of two 3/8-inch plates flush-riveted to each side of the top rail. The cast-iron shoes which serve as guides for the journal boxes also act as s.p.a.cers between the pedestal plates.
The bottom rail of the frame is a 1-1/8-inch diameter rod which is forged square at the pedestals and forms the pedestal cap. The frame is further stiffened by two diagonal rods running from the top of each truck-wheel pedestal to the base of the driving-wheel pedestal, forming a truss. Six rods, riveted to the boiler sh.e.l.l and bolted to the frame"s top rail, strengthen the frame laterally. Four of these rods can be seen easily as they run from the frame to the middle of the boiler; the other two are riveted to the underside of the boiler. The attachment of these rods to the boiler was an undesirable practice, for the boiler sh.e.l.l was thus subjected to the additional strain of the locomotive"s vibrations as it pa.s.sed over the road. In later years, as locomotives grew in size, this practice was avoided and frames were made sufficiently strong to hold the engine"s machinery in line without using the boiler sh.e.l.l.
The front and rear frame beams are of flat iron plate bolted to the frame. The rear beam had been pushed in during an accident, and instead of its being replaced, another plate was riveted on and bent out in the opposite direction to form a pocket for the rear coupling pin. Note that there is no drawbar and that the coupler is merely bolted to the beams.
Since the engine only pulled light trains, the arrangement was sufficiently strong.
RUNNING GEAR
The running gear is simply sprung with individual leaf springs for each axle; it is not connected by equalizing levers. To find an American locomotive not equipped with equalizers is surprising since they were almost a necessity to produce a reasonably smooth ride on the rough tracks of American railroads. Equalizers steadied the motion of the engine by distributing the shock received by any one wheel or axle to all the other wheels and axles so connected, thus minimizing the effects of an uneven roadbed. The author believes that the _Pioneer_ is a hard-riding engine.
The springs of the main drives are mounted in the usual fashion. The rear boiler bracket (fig. 18) is slotted so that the spring hanger may pa.s.s through for its connection with the frame. The spring of the leading wheels is set at right angles to the frame (fig. 27) and bears on a beam, fabricated of iron plate, which in turn bears on the journal boxes. The springs of the trailing wheels are set parallel with the frame and are mounted between the pedestal plates (fig. 18).
The center of the driving wheel is cast iron and has spokes of the old rib pattern, which is a T in cross section, and was used previous to the adoption of the hollow spoke wheel. In the mid-1830"s Baldwin and others used this rib-pattern style of wheel, except that the rib faced inside.
The present driving-wheel centers are unquestionably original. The sister engine _Jenny Lind_ (fig. 22) was equipped with identical driving wheels. The present tires are very thin and beyond their last turning.
They are wrought iron and shrunk to fit the wheel centers. Flush rivets are used for further security. The left wheel, shown in figure 17, is cracked at the hub and is fitted with an iron ring to prevent its breaking.
The truck wheels, of the hollow spoke pattern, are cast iron with chilled treads. They were made by Asa Whitney, one of the leading car-wheel manufacturers in this country, whose extensive plant was located in Philadelphia. Made under Whitney"s patent of 1866, these wheels may well have been added to the _Pioneer_ during the 1871 rebuilding. Railroad wheels were not cast from ordinary cast iron, which was too weak and brittle to stand the severe service for which they were intended, but from a high-quality cast iron similar to that used for cannons. Its tensile strength, which ranged from 31,000 to 36,000 psi, was remarkably high and very nearly approached that of the best wrought-iron plate.
The cylinders are cast iron with an 8-1/2-inch bore about half the size of the cylinders of a standard 8-wheel engine. The cylinders are bolted to the frame but not to the saddle, and are set at a 9 angle to clear the leading wheels and at the same time to line up with the center of the driving-wheel axle. The wood lagging is covered with a decorative bra.s.s jacket. Ornamental bra.s.s jacketing was extensively used on mid-19th-century American locomotives to cover not only the cylinders but steam and sand boxes, check valves, and valve boxes. The greater expense for bra.s.s (Russia iron or painted sheet iron were a cheaper subst.i.tute) was justified by the argument that bra.s.s lasted the life of the engine, and could be reclaimed for sc.r.a.p at a price approaching the original cost; and also that when brightly polished it reflected the heat, preventing loss by radiation, and its bright surface could be seen a great distance, thus helping to prevent accidents at grade crossings.
The reader should be careful not to misconstrue the above arguments simply as rationalization on the part of master mechanics more intent on highly decorative machines than on the practical considerations involved.
The valve box, a separate casting, is fastened to the cylinder casting by six bolts. The side cover plates when removed show only a small opening suitable for inspection and adjustment of the valve. The valve box must be removed to permit repair or removal of the valve. A better understanding of this mechanism and the layout of the parts can be gained from a study of figures 23-26, 28 (8, 8A, and 8B).
[Ill.u.s.tration: Figure 27.--"PIONEER" LOCOMOTIVE. (1) Air chamber, (2) reversing lever, (3) counterweight, (4) reversing shaft, (5) link hanger, (6) rocker, (7) feedwater line to boiler, (8) link block, (9) link, (10) eccentric, (11) pump plunger, (12) pump steamheater line, (13) feedwater pump, (14) wire netting [bonnet], (15) deflecting cone, (16) stack, (17) stack hopper. (Drawing by J. H. White.)]
[Ill.u.s.tration: Figure 28.--REAR ELEVATION of _Pioneer_ and detail of valve shifter; valve face and valve. (Drawing by J. H. White.)]
Both crossheads were originally of cast iron but one of these has been replaced and is of steel. They run into steel guides, bolted at the forward end to the rear cylinder head and supported in the rear by a yoke. The yoke is one of the more finished and better made pieces on the entire engine (fig. 27). The main rod is of the old pattern, round in cross section, and only 1-1/2 inches in diameter at the largest point.
VALVE GEAR
The valve gear is of the Stephenson shifting-link pattern (see fig. 27), a simple and dependable motion used extensively in this country between about 1850 and 1900. The author believes that this is the original valve gear of the _Pioneer_, since the first mention (1854) in the _Annual Report_ of the c.u.mberland Valley Railroad of the style of valve gear used by each engine, states that the _Pioneer_ was equipped with a shifting-link motion. a.s.suming this to be the original valve gear of the _Pioneer_, it must be regarded as an early application, because the Stephenson motion was just being introduced into American locomotive practice in the early 1850"s. Four eccentrics drive the motion; two are for forward motion and two for reverse. The link is split and made of two curved pieces. The rocker is fabricated of several forged pieces keyed and bolted together. On better made engines the rocker would be a one-piece forging. The lower arm of each rocker is curiously shaped, made with a slot so that the link block may be adjusted. Generally, the only adjustment possible was effected by varying the length of the valve stem by the adjusting nuts provided. A simple weight and lever attached to the reversing shaft serve as a counterbalance for the links and thus a.s.sist the engineer in shifting the valve motion. There are eight positions on the quadrant of the reversing lever.
[Ill.u.s.tration: Figure 29.--"PIONEER" on exhibit in old Arts and Industries building, showing the tank and backhead. (Smithsonian photo 48069E.)]
MISCELLANEOUS NOTES
The cab is solid walnut with a natural finish. It is very possible that the second cab was added to the locomotive after the 1862 fire. A bra.s.s gong used by the conductor to signal the engineer is fastened to the underside of the cab roof. This style of gong was in use in the 1850"s and may well be original equipment.
The water tank is in two sections, one part extending below the deck, between the frame. The tank holds 600 gallons of water. The tender holds one cord of wood.
The small pedestal-mounted sandbox was used on several c.u.mberland Valley engines including the _Pioneer_. This box was removed from the engine sometime between 1901 and 1904. It was on the engine at the time of the Carlisle sesquicentennial but disappeared by the time of the St. Louis exposition. Two small sandboxes, mounted on the driving-wheel splash guards, replaced the original box. The large headlamp (fig. 3) apparently disappeared at the same time and was replaced by a crudely made lamp formerly mounted on the cab roof as a backup light. Headlamps of commercial manufacture were carefully finished and made with parabolic reflectors, elaborate burners, and handsomely fitted cases.
Such a lamp could throw a beam of light for 1000 feet. The present lamp has a flat cone-shaped piece of tin for a reflector.
The brushes attached to the pilot were used in the winter to brush snow and loose ice off the rail and thus improve traction. In good weather the brushes were set up to clear the tracks.
[Ill.u.s.tration: Figure 30.--RECONSTRUCTED SANDBOX replaced on the locomotive, August 1962. (Drawing by J. H. White.)]
After the _Pioneer_ had come to the National Museum, it was decided that some refinishing was required to return it as nearly as possible to the state of the original engine. Replacing the sandbox was an obvious change.[20] The bra.s.s cylinder jackets were also replaced. The cab was stripped and carefully refinished as natural wood. The old safety valve was replaced, as already mentioned. Rejacketing the boiler with simulated Russia iron produced a most pleasing effect, adding not only to the authenticity of the display but making the engine appear lighter and relieving the somber blackness which was not characteristic of a locomotive of the 1850"s. Several minor replacements are yet to be done; chiefly among these are the cylinder-c.o.c.k linkage and a proper headlamp.
The question arises, has the engine survived as a true and accurate representation of the original machine built in 1851? In answer, it can be said that although the _Pioneer_ was damaged en route to the c.u.mberland Valley Railroad, modified on receipt, burned in 1862, and operated for altogether nearly 40 years, surprisingly few new appliances have been added, nor has the general arrangement been changed.
Undoubtedly, the main reason the engine is so little changed is that its small size and odd framing did not invite any large investment for extensive alteration for other uses. But there can be no positive answer as to its present variance from the original appearance as represented in the oldest known ill.u.s.tration of it--the Hull drawing of 1871 (fig.
8). There are few, if any, surviving 19th-century locomotives that have not suffered numerous rebuildings and are not greatly altered from the original. The _John Bull_, also in the U.S. National Museum collection, is a good example of a machine many times rebuilt in its 30 years of service.[21] Unless other information is uncovered to the contrary, it can be stated that the _Pioneer_ is a true representation of a light pa.s.senger locomotive of 1851.
_Alba F. Smith_
Alba F. Smith, the man responsible for the purchase of the _Pioneer_, was born in Lebanon, Connecticut, June 28, 1817.[9] Smith showed promise as a mechanic at an early age and by the time he was 22 had established leadpipe works in Norwich. His attention was drawn particularly to locomotives since the tracks of the Norwich and Worcester Railroad pa.s.sed his shop. His attempts to develop a spark arrester for locomotives brought Smith to the favorable attention of Captain Daniel Tyler (1799-1882), president of the Norwich and Worcester Railroad. When Tyler was hired by the c.u.mberland Valley Railroad in 1850 to supervise the line"s rebuilding, he persuaded the managers of that road to hire Smith as superintendent of machinery.[10] Smith was appointed as superintendent of the machine shop of the c.u.mberland Valley Railroad on July 22, 1850.[11] On January 1, 1851, he became superintendent of the road.
In March of 1856 Smith resigned his position with the c.u.mberland Valley Railroad and became superintendent of the Hudson River Railroad, where he remained for only a year. During that time he designed the coal-burning locomotive _Irvington_, rebuilt the Waterman condensing dummy locomotive for use in hauling trains through city streets, and developed a superheater.[12]
After retiring from the Hudson River Railroad he returned to Norwich and became active in enterprises in that area, including the presidency of the Norwich and Worcester Railroad. While the last years of Smith"s life were devoted to administrative work, he found time for mechanical invention as well. In 1862 he patented a safety truck for locomotives, and became president of a concern which controlled the most important patents for such devices.[13] Alba F. Smith died on July 21, 1879, in Norwich, Connecticut.