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America on the Move
Collection Exhibition Themes
Home-made Saddle-Bolt Spanner
Catalog #: 2002.0075.14, Accession #: 2002.0075
Currently on display
From the Smithsonian Collection

Home-made, used in steam locomotive repair work to tighten/remove some very large, critical bolts. Wrench was doubtless used with a very long 'extender' on the handle to gain the necessary leverage.

In removal, the areas around the bolts would have been heated by a torch to help in removal of the bolts. (The temperature differential of bolts and surrounding heated areas would have been small - the bolts themselves absorbing heat in the process - but the differential would have helped in loosening.)

Physical Description
8 1/2" W x 19 " L
Date Made:
ca. 1950s
Dates Used:
1900 - 1960
U.S., possibly made at Green Mt RR, Vt.
Gift of National Park Service

Part of a small array of hand tools displayed in "America On The Move" - such tools were used in the inspection and repair of steam locomotives. Light repairs on steam locomotives were usually done in roundhouses at the many small locomotive terminals throughout a railroad's system; heavy repairs were done in a large, centralized repair shop serving the whole system (often referred to as the "Back Shop"). Most of these tools date from the early- to the mid-20th century, roughly 1900-1955.

The term "spanner" could apply to any size open-end wrench. In the US, the term often applied to open-end wrenches to fit very large nuts and bolts. This spanner - clearly "home-made" in a steam locomotive shop by cutting it out with a torch from a flat sheet of thick steel - was meant to fit the extremely large bolt heads and nuts that hold the front-end (or the "smokebox" portion) of a steam locomotive boiler onto the cast-steel "saddle" that is the foundation of a steam locomotive's cylinder-and-mainframe assembly.

The strength and tightness of these "saddle bolts" that join boiler and saddle are crucial to keeping the locomotive from literally shaking itself apart when underway down the track.

This crude spanner was likely home-made in a roundhouse far from a full repair shop; a well-equipped heavy-repair shop would have had spanners manufactured and well-made. One can speculate that an inspector in a roundhouse may have found a loose saddle bolt - probably more than one. If so, the home-made spanner would have allowed the roundhouse crew to tighten the loose saddle bolt, so that the locomotive could safely move under its own power.

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