3D satellite view of Suffolk Mill

The 90-minute Suffolk Mill and Trolley Tour starts at the Lowell National Historical Park Visitor Center where participants board a trolley bus and ride to what originally opened as Suffolk Mills. The main focus of the tour is how water provided power, and the mill is the only place in Lowell where the public can see a working water-powered turbine from the late 1800s. The Suffolk Mill Turbine Exhibit is also located inside the building.

Tours are typically given on select days from early June through late November, usually in the afternoon. Be sure to get the current schedule at either the National Park Service’s Guided Tours web page for Lowell National Historical Park. As far as I know, participation is limited only by the number of seats on the trolley bus. There is no charge for the tour, but you do need to sign up at the Visitor Center ahead of time.

Suffolk Mills opened in 1831, but most of the buildings you now see were built in the 1860s or later. During the Civil War, with the supply of cotton cut off, many northern mills closed and used the downtime to renovate and install new technology. This resulted in most of the original buildings being torn down. Suffolk Mills remained in business until 1926, at which time the buildings were sold to other textile manufacturers. The last to operate was Wannalancit Mills, which closed in 1981.

Suffolk Mills was originally powered by water from the Western Canal, one of five canals that branches off of the Pawtucket Canal. The mill also flanks the Northern Canal, the last one dug in Lowell (opened in 1848). This canal connects directly to the Merrimack River at Pawtucket Falls and ends at Suffolk Mills. At 100 feet wide, it not only provided more power for the mills situated along its edge, it provided 50 percent more water for the entire canal system.

Northern Canal and Suffolk Mill in Lowell, Massachusetts

As mentioned, the focus of the tour is on how water was used to power the textile mills, and the first stop inside Suffolk Mills is at the working water-powered turbine. If you have ever seen an old grist mill with a waterwheel attached to it, that is essentially what was going on inside the Lowell mills, but on a much greater scale. In fact, when the mills first opened in 1823, waterwheels were still used, but instead of being out in the open, they were housed within the mill buildings and located in the basement. They were much smaller in diameter and very wide, more like a paddle wheel on a steamboat than a waterwheel on a typical grist mill.

The textile mills were literally built on the edge of the canals. Water was let into the building via a sluice gate and traveled to the waterwheels (there were multiple wheels in a large mill) through a sloping pipe called a penstock. The pipes were large enough for a man to walk in, so an enormous amount of water was being used. At the end of the penstock, the water tumbled like a waterfall onto the blades of the waterwheel below. The force of the falling water caused the wheel to spin, like blowing air into a pinwheel.

Waterwheels, however, had a couple of problems. First off, water was wasted as it splashed off the blades and fell to the floor where it ran out of the building through a channel called a tailrace. Second, if the water in the tailrace could not exit fast enough and got too deep, the bottom of the waterwheel would actually be submerged, and this drag slowed down the rate of spin. After all was said and done, only about 65 percent of the water was used to spin the wheel. No big deal, you might think, for water is free. No it’s not. The canals were owned by a private commercial organization called the Proprietors of Locks and Canals, and this organization charged the mills for water used, just like water companies charge homeowners and businesses today. Thus, 35 percent of a mill owner’s water bill was literally going down the drain.

In the mid-1800s, James Francis, the chief engineer of Lowell’s waterpower system, and engineer Uriah Boyden began experimenting with more efficient ways to generate power than with a traditional waterwheel. Frenchman Benoit Fourneyron came up with the idea of a hydraulic turbine in 1820, and Francis and Boyden based their experiments on this, as well as on an inward-flow turbine invented by Samuel Howard in 1838. Their work resulted in what is now called a Francis Turbine: a mixed-flow turbine that, while since modified, is still being used today in many hydroelectric power plants. The first Francis Turbine used in Lowell was installed in Boott Cotton Mills in 1849.

A Francis turbine is like a small, steel waterwheel, but instead of water free falling onto its blades, the turbine is enclosed in a case and the water is released directly into it via an attached pipe system so that no water escapes upon entry and only exits the system through the bottom as intended. In the case of the turbine at Suffolk Mills, an 1897 Victor Turbine, water enters from the side and falls out through the bottom, which is what mixed-flow means. Nearly 90 percent of the water is used to turn the turbine, which effectively saves the mill owner 25 percent on the water bill.

The following video shows how a modern Francis Turbine operates. It may be too technical for most people, but it gives you a general idea of how one works.

So how did the spinning of a waterwheel or a turbine power the looms and other machinery in the mill? After taking a look at the turbine, the tour moves one room over to the location of two flywheels connected by a leather belt. This flywheel-and-belt system represents the second evolution of the power system. The original system used metal drive shafts connected to other metal drive shafts by gears. Imagine a waterwheel with a horizontal shaft sticking out from it with a metal gear at the end. Imagine a separate vertical shaft with a gear on the end that ran up through the floor of the mill. Connect the two shafts by the gears, and as the waterwheel spins, its horizontal shaft turns the vertical shaft. The following photo shows how a drive shaft in one direction can power a drive shaft heading in another direction using gears.

Turbine gears and drive shaft meeting at a right angle

The vertical shaft that ran up through the factory floor was connected by gears to another horizontal shaft called a line shaft that was attached to the ceiling and ran the length of the floor. The line shaft had flywheels on it that where connected by leather belts to flywheels on the actual machines. As the flywheels on the line shaft spun, the belts turned the flywheels on the machines, which caused them to operate. If you visit Boott Cotton Mills Museum, you will see an entire factory floor of looms that are connected to the flywheels, and there is one loom on display in Suffolk Mills as well.

Weave room of Boott Cotton Mills in Lowell, Massachusetts

The shaft and gear system was slow, noisy, and broke often. In 1828, one of the most prolific mechanics at Lowell, Paul Moody, realized that if flywheels and belts could power the machines, larger flywheels and longer belts could power the line shafts. This was the system that was eventually adopted by all American manufacturing plants before electrify became available. The following illustration shows the flywheel and belt system powered by a turbine.

Flywheel and Pulley system

The turbine currently operating at Suffolk Mills was installed as part of a dual turbine. It has a drive shaft that extends through the wall and into the next room where it is attached to a large flywheel. You can see in the following photo that the right turbine no longer exists, but when in operation, this would have been a dual turbine with both connected to the same drive shaft to provide extra horsepower to turn the flywheel.

Working turbine at Suffolk Mill, Lowell National Historical Park

Large flywheel of the Suffolk Mill turbine in Lowell, Massachusetts

The next problem to solve was how to regulate the power so that when less looms were in operation the turbines would produce less power, and when more went on line the turbines would produce more power. The solution is located in the basement, and that’s where the tour heads next.

Let’s say that a set amount of water flowing into the turbine will power 100 looms at a desired speed. If 100 more looms are turned on, the speed of the turbine is going to drop because there is suddenly more resistance, and as a result, all looms are going to run too slow. Likewise, if half of the original 100 looms are turned off, the remaining 50 are going to speed up because with less resistance the turbine will spin faster. Imagine driving an automobile on level terrain. With the gas pedal depressed to a certain point, the car travels at a certain speed. However, if you go up a hill and do not change the position of the gas pedal, the car will go slower. You must push down on the pedal to give the engine more gas in order to maintain the same speed up the hill. Likewise, when going downhill you must ease off the pedal to maintain the same speed.

In order to increase or decrease how fast the turbine spins so that it provides the same amount of power to the looms no matter how many are turned on or off, the flow of water has to be increased or decreased. One solution would be to have somebody on the factory floor run down and tell a guy operating the sluice gates to let in more water because 100 more looms are coming on line, but that’s not very efficient. What is needed is some type of machine to regulate the flow automatically—a cruise control for a turbine. The solution is the green machine in the basement.

This machine is called a fly ball governor. It is located next to the turbines you originally saw. If you could look up through the hole behind the fly ball governor you would see where you were standing a few minutes earlier. A leather belt connects this machine to the shaft on the turbine.

Fly Ball Governor

At the top of the fly ball governor are a bunch of balls attached to ropes that are attached to a spinning shaft. The shaft is turned by the belt connected to the turbine, and thus the speed of the turbine dictates the speed of the spinning shaft, which in turn controls the speed at which the balls spin. Imagine taking a tennis ball on a rope and swinging it over the top of your head. As you spin it faster, the ball rises. If you slow down, the ball drops. With the fly ball governor, if the balls drop below a calibrated height, they cause a lever to open the sluice gates and let in more water. If they spin fast enough to raise them higher than the calibrated height, the lever closes the gates and less water is let it. Thus, if 100 looms suddenly go on line, the turbine will temporarily slow down, the balls will drop, and the sluice gate will open to let in more water until enough is flowing to raise the balls to the calibrated level that keeps the looms working at the proper speed.

The last stop on the tour is the Suffolk Mill Turbine Exhibit (aka River Transformed Exhibit). Here you will find a disassembled turbine (the one missing next to the working turbine) and a drive shaft, plus a few information panels. The Ranger points out the features of the turbine and shaft, but there is no time to look through the exhibit on your own, which is the one negative point of the tour. It’s only held once a day, so there is no rush to clear out before the next group arrives. I see no reason why the tour can’t be extended fifteen minutes so people have a chance to give the exhibit a more thorough examination. Other than that, the Mill and Trolley Tour is on par with any of the more popular canal boat tours. If you enjoy technology, I highly recommend it.

Disassembled turbine at Suffolk Mill in Lowell, Massachusetts

Suffolk Mill Turbine Exhibit, Lowell National Historical Park

Back to the Top