Mechanics of Change


Part of the research scene is the observation and recording of change. Whether the change being observed is relevant or not, understanding the change mechanism can provide a better understanding of past, current or future events and the associated snippets of information. This section has some relevance for rolling stock but specifically deals with changes for buildings, bridges, track geometry, signals and infrastructure works. It can also apply to non rail changes.

Observation of change

At some time or another, we have all witnessed some change whether it has to do with our hobby or not. In fact most of us are aware of change and the planning involved. This discussion is an attempt to quantify all the variables involved: with the change itself and with our perceptions of that change.


From an observer view point there are only two ways to observe change:

  1. Continuous - Observation of continuous change, much like a full length movie
  2. Discrete - Observation of change at repeated intervals, much like watching every 100th frame of a movie

In most cases we never actually observe continuous change. We observe change in a discrete fashion for short continuous lengths of time. Sort of like watching two or three frames with 100 to 200 frame gaps. As a guide to our actual observation time calculate the total number of minutes as a percentage of a year ( M = minutes, % = ( M/60x60x24x365) x 100 ). Yet our perceptions have a greater impact than the viewing time.

Unless we actually see the change, we are only aware of the change from third parties such as newspapers, TV, Internet, books, magazines and passed on by others. The information we get from these sources is flavoured by several factors:

Brain storage

The best analogy I give is with that of a computer. At whatever the level of interest, the brain seems to absorb so much and then after a while, suddenly change doesn't seem to matter. The interest may be there but for some reason the brain doesn't seem to keep a continuous 'thread' on changes like it used to. My analogy is like computer memory where maybe 30% of the capacity is used for day to day stuff. Stuff we like to remember gets laid down on a 'use once' CD-RW. Once that is full, there seems to be a perception that 'too many changes are happening'. This may vary from person to person but I believe this might happen some time in the late 30s, early 40's.

Once this point has been reached, the 'nostalgia' view point seems to kick in. From this point on,or at least within a few years


Who we are, our short and long term goals, and what our knowledge base is will determine how we react to what we observe. Some of the points will be:

  1. Interest level
    1. Low
    2. Moderate
    3. High
    4. Obsessive
  2. Stimuli
    1. Social
    2. Work
    3. Modeling
    4. History
    5. Book
    6. Family
    7. Event
    8. Environment change
  3. Methods
    1. Discussion
    2. Notes
    3. Observation
    4. Photography
    5. Sketches / Diagrams
  4. Understanding
    1. Length of time
    2. Cycles viewed
    3. Contact network
    4. Nostalgia point


The Physical Change

Like the mechanical life cycle, change has a similar cycle from proposal to implementation. Whilst the points below have been highlighted to show a logical progressive path, in many cases the points can become blurred and overlap.

Change Cycle

Change Transition

Change is very subtle. The most important observations for change cover all those points listed below. Yet photographically, the most importants parts are before, during and after. There must be particular emphasis on during because in this phase it is most important to record the new as landmarks against the old.


The changes mentioned above can apply to any change whether it is the introduction of a new train, track re-alignment or new construction. I refer to these changes as 'cycles'. So we end up with a 'New train cycle', 'New wagon cycle' or new deviaton cycle' whereby at the start of the cycle the entire 'Mechanics of Change' kick in from start to finish. 

Peter J. Vincent, March 2003