Travels Through The Harvard Labyrinth

This is the second of two articles on the Harvard Tunnel

Weld Hall, one of nine operating stations in the Tunnel system, regulates the busy Main Yard area of Harvard. Next year, when an electronic data processing unit is put in the basement, Weld will become the control center of the entire system. The office of Mr. Floyd Kingsbury, foreman of the Tunnel engineers, is strategically located next to the room in which this "computer" will reside, and it was here that Mr. Kingsbury gave us a briefing on how Harvard is heated.

Steam from the Cambridge Electric Company's boilers enters the three pipes in the Tunnel at a pressure of one hundred pounds per square inch and a temperature of 425-430 degrees Fahrenheit. (Depending on the needs of the University, one or more of these pipes may be shut down.) After going through reducing valves which lower its pressure to about five pounds per square inch, the steam travels to individual buildings where it heats tanks of water. The Houses and most other buildings outside the Yard have their own water reservoirs, including separate tanks for domestic hot water and radiator water.

Central Supply

Within the Yard, however, water for all buildings comes from a central supply which is heated in and distributed from the Weld operating station. At all times, both in the Yard and outside, the steam remains within a closed network of pipes; but in the process of giving up heat much of it condenses to distilled water. This condensate is collected and pumped (through a small pipe on the floor of the Tunnel) back to the Western Avenue power plant where it is again converted to superheated vapor.

For most of its travels the steam is under automatic control: reducing valves change pressures as heating demands vary, thermostats operate other valves to keep steam flow (and, consequently, water temperatures) at desired levels. The temperature of radiator water is also adjusted automatically according to how cold it is outside: when the air in the Lowell House courtyard is a crisp thirty degrees, for example, the water circulating through House radiators is kept at 140.

Mr. Kingsbury says Buildings and Grounds has enjoyed this degree of automation for at least all of the 39 years he has been with the department. But real modernization began only recently with the installation of a Minneapolis-Honeywell "data board" in the operating station under Langdell Hall. When Holyoke Center opened, a second board was put in the station in its basement, and sometime in 1964-65 a third one will be set up in Weld. In addition, Weld will get a master data processing unit that will collect information gathered by all three boards and put it into concise, easily readable form.

A data board makes it possible to find out what you want to know about a building without actually going inside. In the past, if a complaint came from, say, the Biological Laboratories that rooms were overheated, Buildings and Grounds had to dispatch a North Yard Tunnel man to the Biological Laboratories in order to get readings from the relevant thermometers and pressure guages. Now, whenever he wishes, a man sitting in front of the Langdell Hall data board can find out the air temperature of the Biological Laboratories (or a great many other things about any building in the North Yard) simply by pushing the proper buttons. The Holyoke Center board gives Buildings and Grounds the same flexibility in the South Yard, and things will become just as simple in the Main Yard as soon as the Weld Board is connected.

Electronic sensing devices placed throughout the University account for the capability of these boards to give such quick readings at a distance. When the operator in Langdell pushes a button to get the temperature of the hot water running through the pipes of Mallinckrodt Laboratory, he is actually selecting the circuit which connects an indicator on the board to a special thermometer inside one of the Mallinckrodt pipes. Data boards by themselves are not fully automatic: the operator must decide what readings to take and then press the buttons. Also, a data board does not signal breakdowns in the system as they occur; the operator has to go looking for trouble.

Each board offers over fifty different selections--that is, each can read temperatures or pressures in over fifty different locations. In Holyoke Center and Langdell Hall, engineers go through all of these readings several times a day in order to scan the system for trouble. But next year even this bit of manual work will be unnecessary, since the data processor in Weld will scan all three boards continuously and print out the information on ticker tape. It will also sound an alarm when any of the readings fall outside normal limits.

Communication System

Mr. Kingsbury was about to suggest that we resume our travels through the Tunnel when a loud series of long and short buzzes rang in his office. "That's our own private communication system," he explained. "There are telephones throughout the Tunnel, each with its own code of short and long rings. And when you make a call, the signal sounds on all of the phones. If you ever hear a steady 5-second blast, that means there's an emergency." (He added in passing that emergencies are rare. In fact, no serious explosion of a steam line has ever occurred.)

Holyoke Addition

We decided to begin the rest of our travels by following an overland route to Holyoke Center, where we would inspect the data board, then to travel underground to the river, cross the Charles inside the Weeks Bridge, and finally come up to the surface at the Business School operating station in McCulloch Hall. Mr. Kingsbury wished us well and placed us in the care of another Tunnel engineer, this time a South Yard man.

On the way to Holyoke Center, we asked our guide whether it was usual to connect all new buildings to the Tunnel. He replied that the Tunnel is only extended when new buildings are close by. "Otherwise, the expense is prohibitive, and we just join the pipes through a trench." (A trench is a sort of small trough, big enough for pipes and cables but much too small for people.) Since the Tunnel comes down to Lowell House under Linden Street, Holyoke Center is not too far off the track, and a connection big enough for people was feasible. Instead of constructing a full-scale tunnel, however, Buildings and Grounds economized by joining the Center to the system with a concrete pipe, five feet in diameter.

On arriving at Holyoke Center, we took an elevator to the sub-basement and found ourselves in a room that looked much like the Weld Hall operating station, except that all of the equipment was much newer. In one corner, housed in a glass-enclosed control room, was the Minneapolis-Honeywell data board. With its multitude of buttons, dials, and colored lights, it lived up to our expectations.

Sitting at the board and scanning it was a Mr. McFarlane, who said he could go through all 52 readings in less than ten minutes. When we came in, Mr. McFarlane was carefully checking over temperatures in Holyoke Center itself, because he was afraid the sun load on the building might be causing overheating. But everything seemed to be in order, and Mr. McFarlane proceeded to show off the machine.

He explained that the operator first selects an area for "reading out" by pushing one of a set of buttons marked with letters of the alphabet. He pushed "J" to demonstrate, and after a brief flashing of lights and grinding of gears, a diagram in glowing green lines appeared on a screen set in the control panel. "The board is now projecting a slide of water and steam pipes in area J," said Mr. McFarlane, "which happens to be the Indoor Athletic Building. Now within this area, we can take a number of readings"--he referred here to a book that listed the possibilities and showed us that each site in area J had a number which also appeared on the slide. We noticed that number 10 was labeled "Pool--water temperature."

Heat Indicators

"All we do is push button 10," McFarlane continued as he pushed button 10, "and we find out how warm the I.A.B. pool is." An indicator needle on one of the dials showed that the water was at a very warm 78 degees. By pushing button 11 we found that the temperature of the air above the pool was an even more tropical 85. "The fellows over there tell us to keep it hot, so we do," McFarlane commented. Using other combinations of letters and numbers, we learned the temperature of the Lowell House dining hall (75) and of the water in the radiators of Master Taylor's house (130). It all seemed a great intrusion on personal privacy.

We thanked Mr. McFarlane for the demonstrations and with our guide walked out of the control room, down some steps into the five-foot pipe leading to the Tunnel. The inside turned out to look just as one would expect the inside of a concrete pipe to look; it was cheerfully lit and almost pleasant, however, except that the low "ceiling" made it necessary to walk with a slight stoop. We recognized the usual Tunnel fixtures: steam pipes, electric conduit, telephone cables. The pipe made a number of turns so that we could not be sure of our route, but it seemed that we passed under Elsie's and somewhere near the I.A.B. before turning east. Eventually, the pipe came to an abrupt end, and by climbing down a long metal ladder we entered the Tunnel at a point below Lowell House tower. Because it carries less steam, this pipe is much cooler than the main Tunnel; at Lowell House we got back into the 100-degree climate we had experienced earlier beneath the Yard.

From here on, the route was well-marked. Signs on exit doors to the surface let the explorer know what building he is passing under. The Tunnel goes directly beneath the Lowell House courtyard to Mill Street where it turns sharply east and runs for a short distance between Leverett House (McKinlock Hall) and Quincy House. At DeWolfe Street there is a turn to the south which brings the Tunnel to Memorial Drive and a large junction room know as the "Parkway Header." Like the Widener Chamber, the Parkway Header is a nexus of three Tunnel branches: the one we came through, one to the Business School (this lay directly ahead of us) and one under Memorial Drive to Western Avenue (this was on our left).

Our guide told us we were directly under the Drive. That we could not hear anything of the traffic overhead was probably due to the thickness of the Tunnel roof--fourteen inches of reinforced concrete. In front of Dunster House the Tunnel is so close to the surface that the top of its roof is the sidewalk. No snow, you may have noticed, ever accumulates on the walk in front of Dunster House.

Tight Squeezes

We moved out of the Parkway Header and into the dim passage ahead. At once, the air became quite chilly, and the Tunnel began to climb upwards. "We're approaching the bridge," said the guide, "and we've got three tight squeezes ahead of us." (The Weeks Bridge, we recalled, has three arches; at the top of each, the Tunnel can only be about a yard high.) "Actually, we ourselves don't much use this passage," he went on, as we climbed up the steep curve of the first arch. "When we want to come over to the Business School, we travel on the surface." We began to wish we had been as smart, for by now the roof was so low that we had to scramble awkwardly along a cold, damp floor, and as the curve flattened out at the peak of the arch, we were forced to crawl on hands and knees. Then, at last, we started downhill, again able to walk upright.

At the cramped top of the middle arch we thought of the pedestrians walking just inches above us; how surprised they would have been had they known an expeditionary force was moving silently beneath their feet. Our musings were interrupted by a loud "Hello," from up ahead. It came from Dominic, a friendly other-side-of-the-river Tunnel man who was waiting to take us the rest of the way. Our South Yard guide, having reached the border of his territory, could proceed no farther. We waved goodbye as he turned around to go back, and then, with Dominic encouraging us, squeezed past the third arch on the last leg of this most uncomfortable part of the trip.

Less Steam

Dominic welcomed us to his area of the Tunnel and explained that things were much cooler here (around 50 degrees) because less steam was needed at the Business School than on the Cambridge side. The Tunnel stretched straight out before us. A downward slope took us back underground, and then we started the long walk under the river bank and expressway toward the Business School. An uneventful five minute walk brought us to the McCulloch Hall operating station, from which, after exchanging farewells with Dominic, we left subterranean Harvard and returned to the Harvard of everyday experience.

On the way home--this time going over the Weeks Bridge instead of through it--we considered how remarkable it is that so few members of the Harvard community know anything at all about the more than three miles of tunnels underneath them. A garrulous old bum who used to spend the nights around Leverett House told an undergraduate last year that he often slept inside the Weeks Bridge where "it's warm and quiet." It seems odd that a bum and a Nazi spy should be more familiar with the Tunnel than most undergraduates, especially since the existence of the underground passages is by no means a secret, and Harvard men--at least some of them--are inquisitive. Yet, it is somehow comforting to know that within the University there are still uncharted regions--mysterious worlds in which even the most jaded undergraduate can find new adventure