The decision to  add a bridge to a layout derives from many factors, including period, prototype, topography, and features.   Once the decision is made to erect a structure, then the focus becomes one of appropriate design and style.

Initially, the period drives the process.  All periods have their distinctive prototypes, whether the 1880s, 1920s, 1960s, or any other period.  While an old bridge may exist on a modern layout, a modern bridge would necessarily be very out of place on a layout modeled to a previous time period.  An old bridge on a modern layout would need to be very substantial to justify it’s inclusion in a modern era due to current tonnages.

Next, type becomes of critical importance, and is driven by topography and features.  Trusses span gorges,  and trestles span valleys and low elevations.  Clearance requirements govern selection of types, due to the absence of or accommodation of boat, rail, or highway traffic beneath the bridge.

Once period and type are determined, the next decision is level of detail and adherence to prototype.  This decision is dependent upon the customer’s balance of cost and detail.  Just like any locomotive or rolling stock that you purchase, detail is an important component of cost.  Due to the paucity of commercially-available parts, higher levels of detail mean an enormous increase in labor to produce a level of detail that would earn the label “prototype”.

An appropriate analogy would be an older Athearn “F” unit that you desire to model for a specific railroad.  The time and detail parts will cost you far more than the initial purchase of the locomotive.  So it is with bridge construction.  But dramatic results can be obtained with some judicious decision-making.

Every bolt and rivet are not necessary to produce an exceptional structure.   In most of the examples on this website, such details are absent.  But their absence does not lessen the impact and enjoyment of the structure.  What I do can be described as “value engineering”, i.e. producing a bridge that conveys the engineering essentials of a structure while not driving the cost to extremes by including detail that brings the project to “contest quality”.  Contest quality may be obtained if so desired, but I recognize that cost is a very large consideration.

Materials-

Generally speaking, in model construction we use materials the lend themselves to mimicking the prototype materials.  Examples of this are wood for wood, plastic for steel, and plaster for concrete or masonry.  But this is not cast in stone, if you will pardon the pun.

Although it may not be evident from the images in the “Works” pages on this website, there is great flexibility in what materials are selected.  Some bridges have plastic “concrete” or “masonry”.   Some bridges have wood and cardstock “steel”. Some have wood “concrete”. Viewing the images may not betray this, and that is entirely the point.