One of the popular legends that surrounds Henry Ford is that he
abhorred paper work, especially forms and records. At least where the
design and engineering of the Model T is concerned, quite the opposite
is true.
The engineering department of the Ford Motor Company kept extensive
records regarding each part of the Model T. These records include the
mechanical drawings of the parts themselves, detailed material
specifications for the parts, step by step instructions for producing
the parts, cost records, and a list of changes made in each of the parts
over time.
Many of these records have survived and are now preserved and stored at
the Research Center of the Henry Ford Museum and Greenfield Village.
One of the most important body of records to those interested in
documenting how the Model T evolved over its 19 year production run is
the chronological list of changes for each part. These lists are
officially titled "Record of Changes", but are usually referred to as
the 'releases' by the staff at the Research Center since they also
signified when a change in a part was approved and released for
production.
Unlike a library where books and materials are organized by a catalog
number that is determined by the subject, the Research Center is an
archive. Most of the documents housed there were formerly part of the
Ford Archives (a division of the Ford Motor Company). In an archive,
documents are organized by accession. A body of documents arriving
together at an archive are always kept together, if possible in exactly
the order received. The body of documents is called an accession, and
assigned an accession number. Most of the engineering documents
relating to the Model T are on microfilm and are to be found in
Accession #1701 at the Research Center. One small portion of this
accession are the releases pertaining to the Model T. It appears as
though the collection of releases is virtually complete and that they
cover almost every part ever used on the Model T right down to the nuts,
bolts and cotter pins.
To understand the importance of the releases, one first has to have an
overview of the factory part numbering system and the process by which
changes in parts took place. In the Ford Motor Company during the Model
T era, every item used to make a Model T had a factory number associated
with it. These factory numbers began with the prefix "T" and are
independent of the part numbers found in Model T parts catalogs. For
example, the crankcase was assigned the factory number T-1526. The
crankcase, however, is also an assembly of many other components. The
major components included the large steel stamping of the crankcase
(T-800), the crankcase arms (T-815), the front support forging (T-801),
the front wall (T-808), the front radius rod ball socket (T-809), the
rear flange (T-899) and the drain plug (T-817). Even the rivets used
to assemble the crankcase had T numbers assigned to them.
When the Ford engineers decided to change a component of the Model T,
the blueprints drawings of the new design were drafted, and the new
design was approved for production in a "factory letter". The letter
would detail all of the design changes that were being approved on that
date and the name of the factory official who was approving the
changes. The changes were then entered on the "Record of Changes" form
for the particular T-numbered component being changed. Thus the
releases provide a description of the change, who authorized the change,
the number of the factory letter authorizing the change, and the DATE of
the change.
Another interesting feature of the factory numbering system was how the
number changed when the change in the component was major. Take for
example the crankcase lower cover, T-1582. When the four dip pan was
introduced in 1924, a new, larger design crankcase lower cover was
used. To distinguish the new cover from the old, the T number for the
new cover was give a "B" suffix to become T-1582B. Old three dip design
was re-designated as T-1582A. Since the new four dip lower cover was
not interchangeable with the lower cover on older three dip pans, it was
necessary to continue the old cover in production as a replacement
part. To indicate this status the part was given an additional "R"
suffix to become T-1582AR.
As already mentioned, one of the most significant aspects of the
releases are the dates of the changes. However, it should be emphasized
that this date represents the day the change was adopted, not the actual
date that production of the modified component began. In the majority
of circumstances, the modified part appeared in production after the
date of adoption specified in the release. The time lag between
adoption and appearance in production varies between components from as
little as a few days to as much as six months, but in general modified
parts appeared in production not long after the date specified in the
releases.
It should also be noted that even when a new design part was adopted,
the old design may have continued in production for some time
thereafter. This is because new machinery may have been required to
produce the part of the new design. For example, the release for the
single valve cover engine blocks states that this design was approved on
October 18, 1921 and that the new design was to be initially produced at
the rate of 100 per day. During the next six months the production of
the one piece valve cover cylinder was increased and the old two piece
valve cover design was phased out. But during that period, cars using
both designs of cylinder blocks were produced.
Model T owners who wish to use the releases to make sure their car uses
the correct style parts should keep in mind that the dates specified in
the releases are the first possible date that the new design could have
appeared. Older designs may have remained in production for some time
after the new designs were approved for use.
