Early Heisler & Late Garratt Burners
Nelson Riedel, Nelson@NelsonsLocomotive.com
12/142008, last updated 12/14/2008

I'm in the process of designing  the Heisler oil burner and fire pan and have been  using some recent photos sent by Mike Getscher as well as some photos of Garratt burners so I thought I'd add that data for reference.

Mike Getscher sent the follow three photos of the Pickering Lumber No 2 Oil Burner.  The locomotive is a 75 ton three truck Heisler built in 1918.  It is currently exhibited in Griffith Park, Los Angeles. The photo at right shows the oil nozzle and a hinged damper.  Note that the fire pan is fitted part way up into the fire box
This shows the damper at a slightly different angle and gives a good perspective of the curved bottom of the fire pan.
This photo was taken from near the front of the fire pan looking toward the rear.  The profile of the curved fire pan and the relationship to the bottom of the boiler is clear. Mike was intrigued by the small chute near rear of the fire pan.  It looks like there was an identical one on the other  side.  I believe this chute is an air input vent.   The piece inside the vent is probably a damper.   It is my understanding that early oil burners has these side vents.   Later designs had vents in the firebox door in place of these side vents.   More photos of Pickering Lumber No 2 are at: Pickering Lumber No 2 .

The photo above is of a drawing of the late Garratt Locomotives used on the East African Railroad.  The data at the right is displayed below the drawing.  The drawing and several of the late Garratts are on display at the Railroad Museum in Nairobi, Kenya.   Additional photos taken at the museum are at Garratts .
This shows the inside of a fire box.  Note that there are two burners.   The fire pan sides are covered with fire bricks.  The bottom of the fire pan seems to be covered with a refractory  material.  The hump in the middle is for the steam feed pipe to the rear cylinders.
This is the front of a fire pan identical to the one in the previous photo except the burner nozzles have been removed.   This shows the steam feed line to the rear cylinders passing under the middle of the firebox.  These Garratts are articulated --- there is a hinge at each end of the middle section.  The main steam feed has as a high pressure swivel joint at each hinge point.  A length of flexible rubber hose is used in the exhaust line at the hinge.
This shows the front of a fire box with a burner nozzle installed.   The large pipe going in the bottom is the oil feed.   The smaller pipe going in on the left is the steam.
There is a draft vent in the fire box door similar to that on MRSR91.   I was not interested in the doors when I visited.   I found images of the door in the corner of photos taken in the cab but the photos aren't the best.   This photo shows the closed door
Note that there is a rectangular vent pipe under the fire box door visible here with the door open.
This shows the damper inside the fire box door.  When the door is closed, the damper controls draft  coming up the rectangular vent pipe from under the cab floor, through the door and into the firebox.   I assume this elaborate arrangement is used rather than just opening the door to prevent flashes of fire from coming into the cab.      This door is similar in concept to the door on MRSR91.

The Heisler and Garratt have similar size openings around the burner nozzle for combustion air. (See MRsR91 Burner for photos of that burner).   The Heislers have a damper on the combustion air and the Garratts don't.   I suspect that the damper permits a greater range of oil feed to the burner.

The later Heisler and the late Garratts have vents in the fire box door with a damper to control the vent opening.  The early Heisler appears to have vents with adjustable dampers at the rear of the fire pan.

I tried some vents at the rear of the fire pan on the Shay with little effect (see More Power).   I now suspect that on the prototype the rear vents are used to reduce excessive draft which might blow out the fire.   This could happen when the exhaust is creating a lot of draft--- possibly when under a very heavy load.    I think I'll make a door with a vent and damper for the Heisler and try opening it when the locomotive is under heavy load.