Steam & Excursion > Monday Museum Steam: The Tom Thumb

In 1926 the B&O built what it thought was an operating replica of Peter Cooper's original locomotive which had been built sometime in the mid-1830's in Baltimore. This replica was first exhibited at the U.S. Sesquicentennial in Philadelphia in 1926. It was then featured at the 1927 Fair of the Iron Horse. Now in the collection of the B&O Railroad Museum, it operated irregularly up until the 1990's. Reportedly it was first named "The Tom Thumb" in 1868.

1) First photo is by the late Tom Arnold, showing an excursion in West Baltimore, late 1970's or early 1980's.

2) I had the good fortune to operate it in 1996, here on the museum's first mile of trackage.

3) The late Tom Arnold and I on the locomotive in 1996.

See next post for the stamp and story featuring "the race."

B&O Bill



Edited 1 time(s). Last edit at 08/26/24 05:24 by bandob.

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Photo #1 shows a staging of the alleged race between the train and a horsecar. I say "alleged" because the museum had no proof that it ever happened and some feel it was a product of the B&O Railroad public relations department.  Photo by the late Tom Arnold, circa 1977.

#2) The 1952 Commemorative Stamp noting the 125th Anniversary of the railroad's charter featured a horse, the Tom Thumb, and a modern diesel. The story of the alleged race also made many elementary school history books.

#3) Photo at Halethorpe MD, circa 1977, by the late Tom Arnold. Tom was a retired B&O freight conductor, who was an avid enthusiast and well-versed in operating all the museum steam replicas.

The replica remains on display in the Museum Roundhouse.

B&O Bill



Edited 1 time(s). Last edit at 08/26/24 05:27 by bandob.

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All great photos, Bill.  I have seen the engine several times under steam.  I do not remember the exact date or year now, but when the B&O Railroad Station in old Ellicott City (originally Ellicott Mills when the railroad built, the first 13 miles of track) was deeded over the Howard County Government, the Tom Thumb was hauled out to Ellicott City on a truck and lifted onto the main CSX Track and operated several times up and down the line as part of this ceremony.  See the photos attached.  I just wish that I could remember the date.
John in White Marsh, Maryland

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Wonderful photos - I believe this is your best posting yet!
Bob

Very enjoyable series!

Larry

This is great!  Some questions.  I see no provision for water supply to the boiler.  Is there one?  What was the range in operating practice?  Wht all the men in white coats?   Did they think engineers were crazy?

I think you'll see an extension on the upper end of the 
piston rod.

For the original ( 1800s) Tom Thumb, it was the days before large machine-shop tools,
so the upper end of the piston rod rides between two upright 'guide-rods'. 
An extension off one end of the vertically-travelling 'cross-head', has a short 
extension and an attached, long, vertical  'plunger-rod', operating in a water-cylinder --- 
for forcing water into the boiler --- against boiler pressure..

Plunger-rods, with no piston-head were used in early water pumps, again because
no such machinery existed, to produce precision cylinder walls, piston & rods, etc...
So, the pump operates with a plain rod end reciprocating in the water space.  
The water pumped into the boiler is equivalent to the volume displaced by
the 'plunger'... with every down-stroke of the plunger.
There is a check-valve at each end of the pumping cylinder, so that pressured
water cannot get pumped back into the wooden, supply-barrel.

While standing, a loco would be uncoupled from its train and run, back-and-forth 
in order to pump water into the boiler.  Live steam injectors were not patented until 
about 1870.

Since this is a replica built in the 1920's, the boiler had to comply with the 
existing ICC Steam Loco Ruies, and I believe I remember seeing an injector
on one side of it's boiler....a 20th century requirement.  So, on the replica,
no back-and-forth movements were necessary, while standing-around, under steam.
( the "requirement" is that you need to have two means to add boiler water, when
  under boiler pressure; in practice, it's two injectors, or one injector & one pump)

As a lad, I spent many hours and took many pics of, & notes on, all the engines in the
B&O museum....   At that time, about 1965 & '66

​W.

( In photo 2, above, the water barrel for boiler water is seen above the 
  word " PETER".... Photo 8, also, clearly shows the water barrel --- at the corner
  
  In the back ground is an operating replica of The Best Friend of Charleston,
  a southern loco who's hissing safety valve was silenced with a heavier weight,
  than it's builder had provided.  The annoyed fireman's action resulted in the 
  invevitable explosion of the original's boiler.  Like the original Tom Thumb, reliable
 boiler gauges had not yet been in vented.  Early safety valves were held closed by a long,
 weighted lever.  There were notches on the lever's outer end for pressure 'adjustments'
 
   Maximum, Safe Boiler pressures were determined mathematically, by the boilers' builders,
   based on the lever's length, the mass of the weight, and the area of the seated plug-valve.
   Spring-regulated safety valves, became available after about 1885., as well as dial-tyoe
   boiler pressure gauges.  It was harder to tamper with the spring-closed safety valves.

   Reliable, dial-type boiler gauges had not yet been invented, or manufactured 
   until the 1870s.   Also, safe boiler water-levels were determined by 3 manually operated
   boiler-cocks ---- with a mix of steam & water out of #2 try-cock, when testing - was 
   the desired, proper, water-level.  Yes, you can call the 3 valves: tri-cocks, if you prefer
   The upper cock should normally be steam-only;  the bottom cock should ALWAYS
    show water, only! when gently tested.

    After the FRA Steam Loco Law was changed in the year 2000, two 'water-glasses'
    are mandated;  the retention of 3, well-maintained tri-cocks is optional, now.
    The supply pipes, into the boiler,  for water glasses and tri-cocks MUST
     reamed and cleaned every 30-day boiler-wash, as mandated by the Law.  

     Typically, the lower supply pipe to the water glasses, and tri-cocks becomes plugged
     with solidified calcium-salts in the boiler water, so the short supply-piping must be
      routinely reamed of accumulated, solidified, boiler-salt.  A suitable sized  ( diameter)
      modern drill bit is used to manually remove all accumulated encrustation from the
       pipe's internal diameter).
    



Edited 15 time(s). Last edit at 08/27/24 13:44 by wcamp1472.

There is footage of the Tom Thumb running in the 1950's at Ellicott City in our video "Glory Machines Volume 2".
It was filmed by Chuck Snyder, whose 16mm film makes up most of that DVD.

Jim Herron
Herron Rail Video