PATTERNMAKING

 

Among the thousands and thousands of parts that make up a steam locomotive, most do not get made anymore; most of the suppliers who made the myriad castings, fittings, appliances, etc., etc., have long since gone out of business.

 

In order to get our locomotive back up and running, we have had to make many, MANY parts ourselves, and have many, MANY more made for us.  This page explains just one of the processes involved.

CASTINGS

 

A steam locomotive has literally hundreds of cast metal parts, in steel, iron, brass, bronze, and other metals.

 

"Casting is a manufacturing process by which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify.  The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process.  Casting materials are usually metals or various cold setting materials that cure after mixing two or more components together; examples are epoxy, concrete, plaster and clay.  Casting is most often used for making complex shapes that would be otherwise difficult or uneconomical to make by other methods.  Casting is a 6000 year old process.  The oldest surviving casting is a copper frog from 3200 BC."                          -- Wikipedia

PATTERNS

 

"In casting, a pattern is a replica of the object to be cast, used to prepare the cavity into which molten material will be poured during the casting process. Patterns used in sand casting may be made of wood, metal, plastics or other materials. Patterns are made to exacting standards of construction, so that they can last for a reasonable length of time, according to the quality grade of the pattern being built, and so that they will repeatably provide a dimensionally acceptable casting.

 

"The making of patterns, called patternmaking (sometimes styled pattern-making or pattern making), is a skilled trade that is related to the trades of tool and die making and moldmaking, but also often incorporates elements of fine woodworking. Patternmakers (sometimes styled pattern-makers or pattern makers) learn their skills through apprenticeships and trade schools over many years of experience. Although an engineer may help to design the pattern, it is usually a patternmaker who executes the design."                         -- Wikipedia

THE PATTERNMAKER

 

Bernie Perch, native and resident of White Haven, has made more patterns for the engine than even he can count.  In addition to the ones shown here, he has made patterns for boiler washout plugs, check valves, and dozens of other parts, without any one of which the engine could not operate.  Bernie worked for 34 years for the Crestwood School District and continues to teach pottery classes at the school;  he has also provided the cover paintings for four books on Anthracite Region railroads.

 

To get an idea of the intricacy of the patternmaker's craft, look closely at the area within the red circle in the photo at right.  Keen eyes will discern no fewer than six separate pieces of wood: the two horizontals at the top and bottom of the circle, each about half an inch thick; two separate pieces, each about a quarter of an inch thick, make up the vertical divider; and two VERY small quarter-round "fillets" fair the vertical and horizontal surfaces.  Hidden by the circle itself, two more fillets on the opposite side of the divider.  Multiply this by about ninety and add in all of the other details of the grate pattern and you will understand why we think it entirely appropriate for Bernie to "sign" all of his work!  The raised letters on the pattern appear exactly like this on each of the finished grate castings.

In this photo we see the wooden pattern for one of the locomotive's firebox grates, looking at the bottom; in the background, some of the finished castings.  Grates lead a hard life, with intense heat above and ambient air below, and they have to move, rotating around their long axis so ashes and clinkers can drop into the ashpan.  Since grates break with some frequency, we had extras made, in cast iron with some alloys added to resist cracking.

Three rows of grates run the length of the firebox.  Almost all of the air for combustion comes up through the openings in the grates, so although the coal covers the tops of the grates completely, the fire has to have enough "holes" to allow air to flow.  Poor coal can lead to "clinkers" that form from coal that melts instead of burning, and this can lead to poor enough combustion that a locomotive will fail on the road.  In addition to shoveling coal in through the fire doors in the cab, the fireman also uses a long two-pronged rake to help prevent clinkers from forming, and to move hotter coals into cold spots that can form on the grates.  Hard coal does not burn easily, and 113's firemen have had to learn on the job how to build a proper fire!

Three photos from Bernie Perch

SAND CASTING

 

Just as one would expect from its name, in sand casting one makes a mold out of sand in the exact negative shape of the desired part, i.e. one packs moist sand around the pattern and then withdraws the pattern, leaving an empty space in which to pour the molten metal.  This takes great care in a number of ways: One has to pack the sand perfectly around all of the nooks and crannies of the pattern; the sand has to hold together under the onslaught of hot metal, and one has to take great care not to get in the way of that hot metal!  Iron used in castings flows at approximately 2100 degrees Fahrenheit, steel at between 2600 and 2800 degrees; brass melts in the comparitively low 1800 degree range.

 

Sometimes one cannot pull the pattern out of the mold, due to its complex shape; in that case, one uses the "lost pattern" process whereby the incoming hot metal melts or burns away the pattern.  We had a new smokestack made for 113 using the "lost Styrofoam" process, which meant carving a full-sized pattern of the stack and other associated parts out of Styrofoam at the Behler Patterns, Inc. in Deer Lake, north of Reading (at left).  The Williamsport Foundry did the actual casting.  How do you think the craftsmen at Alco did this in 1923, a generation before the invention of Styrofoam (at Dow Chemical)?

Other castings on the locomotive include the alloy-cast-iron front tender steps (one seen here with its pattern) and the bronze crosshead oil cups -- very small but vital parts that serve to lubricate the bearing surfaces between the crosshead and its guides, right behind the main cylidners.  It takes multiple patterns to make each oil cup.

Some of the locomotive's "jewelry" gets cast as well.  The whistle -- an exact replica of a CNJ three-chime -- has a bowl and valve (the bottom portion) made by Jeff Hosford in California and a cast bronze "bell" made from Bernie's patterns; it takes at least half a dozen patterns to make the whistle.  Bernie measured an actual CNJ whistle, creating drawings (by hand, not on a computer), and then making the wooden patterns.  Active Brass Foundry in Telford, Pa., cast 113's bronze whistle bell.

 

Because a sand-casting process produces a somewhat rough surface right out of the mold, it takes a lot of grinding and polishing to make a whistle shine like this one.

 

The number plate also got cast, in this case in stainless steel -- numbers and backing plate cast integral.  You can order your own three- or four-digit plate from us, your choice of number.  This will look great on your own locomotive, or front door, or mantlepiece . . .

The photos in this column, above and to the right and below, show some of the stages of casting the whistle bells; the locomotive only wears one of these, but collectors have ordered others, and while very expensive, their costs does come down when done in batches.

 

The top photo shows some of the wooden patterns with a finished whistle bell; next, three cores lined up (these make the "negative" part of the casting, i.e. the interior empty space of the whistle). Below that, the empty mold, and then the mold with cores in place.  At the bottom, four factory-fresh castings, still rough -- quite a difference from the shiny whistle bell in the top photo!

 

The three photos at right courtesy of Bernie Perch.

BRAKES

 

In the summer of 2015, replacement of a broken brake shoe on the left-side center driver also led to replacement of the brake cylinder head on that side of the locomotive.  In order to operate through sharply-curved track, 113 has "blind" center drivers, i.e. with no flanges on the inside edges; all of her other flanges keep the wheels on top of the rails, steering the engine and tender through curves.  Brake shoes on all wheels have to conform to the wheels' profiles, and the shoe on a blind driver does not match that on a flanged wheel.  The brake shoe, cast in iron, must also match the arc of the wheel, and with much larger drive wheels than modern diesel locomotives or freight cars, 113 requires custom-made shoes -- as with so many other parts!  Bernie Perch made patterns for the new shoe, and our foundry cast it.  After machining, it looked bright and shiny, as you see it here.

 

Brake shoe and cylinder pictures © Bernie Perch

When the new brake shoe went onto the engine, something did not feel right, the brake rigging not fitting together as it had before.  Further investigation revealed that the head on the left-side brake cylinder had cracked (below left).  Once again, Bernie fired up his woodworking tools and made a new pattern, including additional gussets for strength (center photo).  The newly-cast part appears at lower right.  For a picture of the cylinder head with its mate from the other end of the cylinder, and the interior spring, see the "News and Events" page.

For more about the rest of the restoration process, click here and here.

© 2014-20 Railway Restoration Project 113       113 East Sunbury Street    Minersville PA  17954     570-544-8300     rrproject113@hotmail.com

 

All photos not otherwise credited  © rrproject113.org                                                                                Web site built and maintained by  Oren B. Helbok

 

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