Cresting the hill and descending Main Street into Burlington, Vt., presents a view that never gets old. Laid out before you as you head down the street are downtown Burlington, Lake Champlain and a spectacular view of the Adirondack Mountains. It's as if Main Street runs straight down into the lake, which, in fact, it almost does.
Actually, it dead ends at the Lake Champlain Ferry Dock, where any one of a number of ferry services operated by the Lake Champlain Transportation Co. ply the waters between Vermont and New York state. And this is where our story begins, on the vehicle and passenger-carrying ferryboat Champlain.
Built in Baltimore at the Maryland Dry Dock Co. and lunched in Jan. 1930, this 650-ton ferryboat can hold 35 vehicles and 340 passengers. And any engine enthusiast with a finely tuned ear boarding this vessel will soon lock on to the melodious tone of an engine that signals, 'I need to go and check that out.'
The Fairbanks-Morse Engine
A hatchway and a steep ladder lead you down to the source, and once you've climbed down there's a feeling of having dropped through a time portal as you are confronted with a resplendent Fairbanks-Morse (FM) from the 1920s. And not just a run-of-the-mill FM, either, but a 550 HP, 6-cylinder, 2-stroke diesel, packed into an engine room with all the other ancillary machinery necessary for the operation of the ship, including a workshop.
The engine configuration for shipboard operation has drive shafts exiting both ends of the engine. One shaft is directly coupled aft to the aft propeller and the other runs forward to the forward propeller. A single flywheel is mounted on the aft engine shaft. The ferryboat is designed to sail either bow forward or stern forward, and hence the aft and forward propellers are always turning and are reversed by reversing the engine rotation (a useful feature of 2-stroke engines). This aids in docking and exiting, eliminating the need to keep turning the vessel around. Vehicle boarding and disembarking can take place from either end of the vessel.
Engine commands are received from the captain in the pilothouse on the upper deck via an old style ship's telegraph. Engine start/stop, ahead/astern (forward/reverse) and engine speed are controlled by means of separate maneuvering and throttle controls. Engine starting is by compressed air, which is admitted to the combustion chambers through timed poppet valves. There are two sets of air-start cams, one for ahead rotation and one for astern rotation. The cam followers are shifted to either position by the maneuvering wheel control. To start the engine ahead, the maneuvering wheel is turned briefly to the 'ahead start' position, admitting air into the cylinders and forcing the engine to turn over. The control wheel is then brought back to the 'run' position, disconnecting the compressed air and allowing the fuel injection process to begin and the engine to pick up and run under its own power, engine speed being set by the throttle control.
Engineer John Paul at the controls of the Fairbanks-Morse. The wheel to his left controls the air-start cams for ahead or astern engine rotation.
A characteristic of 2-stroke engines is that they can be run in either direction, so when it is necessary to reverse the ship's direction the engine is reversed. This is done by reducing engine speed and turning the maneuvering control to the stop position. As the engine comes to a stop the maneuvering control is moved swiftly to the astern start position (shifting the cam followers to the correct set of cam lobes) and with a quick charge of compressed air the engine reverses rotation. The maneuvering wheel is then brought back to the astern run position, re-enabling the fuel injection. The fuel injection timing cam is fixed so that injection takes place before top center of the piston in either rotation direction.
Keeping it Working
Now in its 73rd year of operation, this engine has an outstanding reliability record. An important requirement for maintaining uninterrupted ferry service, this reliability has not happened by itself and is the result of a well-planned maintenance schedule carried out during the winter months. This particular vessel doesn't operate in the winter, but others in the fleet do, being equipped with special reinforced hulls for ice breaking so they can maintain a navigable channel thought the lake ice.
One of the difficulties in maintaining an engine this old is a lack of spare parts, as FM no longer supports this engine model. Some parts, such as piston rings, gaskets can still be made or obtained, and the pouring of new babbitt bearings can be carried out by a skilled machinist. A practice of 'innovative scrounging' is necessary for acquiring parts, and this has turned up some surprising caches of parts across the U.S. In 1977 several pistons and cylinders were acquired from a fishing fleet in Maine, but in 1982 the mother lode, so to speak, was struck in the Alaskan Gold Mine Co. operation in Nome, Alaska. It was there that three, 5-cylinder FM models that had been driving an electrical power generation station (this style FM engine was popular for electrical power generation) were found. A trip up to Nome provided cylinders, heads, pistons - as well as hundreds of small parts like gaskets, bearings, fuel injectors, etc. Many of the parts had been meticulously packaged for storage while others had been out in the elements. But, due to the cold air and low humidity they had survived well. It would appear that when you get far north nothing is scrapped, simply ending up abandoned due to the high cost of shipping anything out. All told, 15 tons of parts were packed up and flown to Anchorage and from there trucked to Vermont. As an aside, there were also four older Workspove engines up at Nome, abandoned but probably restorable.
Typical engine maintenance will see the pistons removed and decoked along with the ports. Bearings are checked and the oil and cooling systems are flushed, all 180 gallons! If any outer hull panels on the ships structure have to be replaced or if work needs to be done on the propellers and drive shafts, it is necessary to realign the engine and drive shafts. This is a job requiring infinite patience, using precision adjustable mounts and shims to ensure the engine crankshaft runs true inside the engine housing and that the propeller drive shafts are aligned with the engine shafts and running true along their 65-foot length.
If any one knows of another stash of parts for this model engine, be sure to let us know. And if you are ever in the Lake Champlain area, take a trip on the ferry boat Champlain, making sure to stop by the engine room to see this grand engine in operation.
Contact engine enthusiasts Ivor Hughes at: 212 Rotax Rd., North Ferrisburg, VT 05473. John Paul is an engineer with the Lake Champlain Transportation Co., Burlington, Vt.
Engineer John Paul stands next to the engine showing the ship's telegraph and engine controls. In addition to the wheel control and telegraph, there is a separate throttle control.
Year 1929 Model 37D14 Serial Number 730494 550 HP at 250 rpm 6-cylinder 2-stroke diesel
Weight: 30 tons
Dimensions: 18-fool long. 4-foot wide, 8-foot high
Piston stroke: 17 inches
Bore diameter: 14 inches
Output shaft diameter: 6 inches
Compressed air start pressure/air storage capacity: 250 PSI/Six air receivers at 35 cubic feet each
Oil lubrication system capacity: 180 gallons of lubricant
Oil pressure: 12-20 psi
Oil feed: Electrical pump, 7.5 HP, fed through heat exchanger for cooling
Raw water pump: Bi-directional, driven off engine shaft for heat exchangers
Cooling water system: Engine water jacket, heat exchanger circulation by 7.5 HP electrical pump
Compressed air generation: Two 120 VDC electrical driven compressors, one 3 HP Fairbanks-Morse for topping up pressure, one 10 HP Quincy (main compressor for pressurizing air receivers)
Electrical power generators - two sources for generating 120 VDC, one source for 120 VAC:
Caterpillar 318D: 75 KW, 120 VDC
Caterpillar 3304: 55 KW, 120 VDC
120 VDC to 120 VAC
17 KW and 7 KW