As independent companies built railroad lines in the 19th century, each company chose a different track gauge – the distance between the inner rails – for their track. As the railway industry first grew out of the need to transport mined materials, most early railroad companies chose a gauge that approximated the distance between the wheels of a horse drawn cart. Although stories linking the distance between the wheels of the cart to standards established by the Romans to build chariots, little evidence exists to support this view. More likely, railroad companies utilized existing carts as a model for building their railroad cars and engines, and matched their track gauge to those carts.
The standard gauge – also known as the Stephenson gauge after George Stephenson, International gauge or normal gauge – makes up more than 60% of all the railroad track in the world. In the United States, Canada and Britain the distance is 4 feet 8 ½ inches, and in the rest of the world 1,435 mm, with the latter representing approximately a ½ mm variance and acceptable track tolerance.
In the early 1970s, Larry Weed, MD further developed his structured documentation approach and described the problem-oriented medical record (POMR). This approach organized the medical record around patient problems with underlying structure based upon his SOAP note approach. Over many years of evangelizing by Dr. Weed and others, the POMR and its underlying SOAP structure became the de-facto “standard” for documenting patient care. Nevertheless, this “standard” was not universally applied nor followed by organizations or clinicians.
Excerpts from: Railroads, Weed and EMRs. PSQH, July/August, 2014