This past Sunday morning, despite a forecast hinting at thunderstorms, I found myself heading downtown for a New York Transit Museum tour. The destination? The Cliff Street substation and its surrounding historic neighborhood. As a bit of a substation tour enthusiast, this marked my fourth such exploration, and each one offers a unique glimpse into the city’s vital infrastructure.
The weather, however, had other plans than the forecast. Even on the subway ride downtown to the Financial District, the humidity was palpable. Undeterred by the sticky heat, I made my way from the subway stop towards South Street Seaport. My smartphone guided me to a pedestrian plaza, just off Cliff Street, where the substation tour was set to begin. After a quick check-in with the museum staff, I sought out a rare patch of shade to wait for the tour to commence.
My gaze drifted upwards to the substation building itself. The imposing brick facade, adorned with subtle art deco touches, immediately brought to mind the Greenwich substation. It was clear these structures were indeed siblings, born from a similar architectural and functional necessity.
Around me, fellow tour participants were engrossed in the information packets provided, cameras at the ready, and water bottles in hand, all trying to beat the summer heat.
A few minutes ahead of schedule, we were ushered through the substation’s towering doorway. The familiar face of our tour guide greeted us – a veteran of previous substation tours. He switched on his microphone to overcome the constant, noticeable hum of the equipment – a sound common to all these facilities.
He began by painting a picture of mass transit’s early days in New York, from the electrification of the elevated train lines to the grand opening of the first subway in 1904, and finally, the ambitious planning of the Independent Subway System (IND) in the 1920s. A recurring theme throughout his narrative was the ever-growing demand from riders. Trains were constantly overcrowded, and the call for service to new neighborhoods was relentless.
Power infrastructure had to keep pace with this rapid expansion. The initial subway companies, the Interborough Rapid Transit Company (IRT) and Brooklyn Rapid Transit Company (BRT), later known as BMT, established their own power plants to fuel their networks. Substations, strategically located along the train routes, played a crucial role in converting high voltage Alternating Current (AC) power to 625 volts Direct Current (DC) – the necessary current for the trains. The IND system adopted a similar substation strategy, including Cliff Street Substation (#7), but opted to source commercial power instead of generating it independently.
Trying to capture the wealth of information, I diligently took notes as our guide spoke. His depth of knowledge always surpasses my ability to record everything. Even after several tours, the intricacies of electrical engineering and the nuances of subway history still feel somewhat elusive. It’s definitely an ongoing learning journey! While absorbing the historical context, I couldn’t help but look up at the immense height of the substation’s interior. A massive crane dominated the space overhead, clearly designed for moving heavy equipment in and out of the facility.
Near the entrance gate, a small group of onlookers had gathered. Earlier, while waiting for the tour to start, I’d overheard curious passersby asking museum staff about our purpose. I suspected these individuals were driven by similar curiosity, and I secretly hoped they might be inspired to explore the often-hidden world of urban infrastructure and perhaps even engage with the Transit Museum.
During his introductory overview, our guide circulated large, color photographs depicting the substation in earlier times. One image revealed the aftermath of a flashover in 2002, showing damage to a piece of equipment that has since been replaced.
We then moved deeper into the building, navigating around complex machinery towards the rear. A zigzagging staircase ascended to our left. Our guide paused us amidst towering blocks of grey machines, dwarfing everyone in the group.
He began to explain the modernization process that the Cliff Street substation, like many others, had undergone, albeit with variations in timing. Initially, power conversion was achieved using massive rotary converter machines. Though no longer in service anywhere, I had encountered a few of these relics in previous substation tours, and the photo we had just seen also featured one. Resembling colossal metal donuts, perhaps eight to ten feet in diameter, they stood upright, partially extending into the floor below. Their sheer size made them visually striking. Within the spinning ring, metal brushes facilitated the conversion of alternating current to direct current.
The modernization efforts replaced these behemoths with solid-state rectifiers. The cabinets housing these rectifiers presented a stark contrast to the rotaries – stoic, sterile, and immobile. They resembled banks of computers from the 1960s, albeit with considerably fewer blinking lights.
Other components also underwent updates during the modernization, he noted. Positioned centrally on the floor was a waist-high, intricate box: a contemporary, high-tolerance circuit breaker.
At the far wall, more evidence of the substation’s past and present was on display. Our guide pointed out a large black panel illustrating the power layout of nearby subway lines, punctuated with buttons at intervals. This, he explained, was the former power monitoring and control system, capable only of indicating whether the power was on or off. Adjacent to it was a smaller black box with a touchscreen map of the same area. This modern equipment offered far more detailed information about power flow, significantly aiding in troubleshooting.
As we rounded a corner to head back towards the front of the building along the opposite side, our guide fielded questions about a “radiator-looking thing.” I believe he identified it as a component of a transformer.
Looking up at the giant crane once more, I noticed the inscription “Cleveland Crane.” Could this machine have originated from my own hometown?
Our guide then touched upon the critical aspect of cooling within the substation, particularly essential when the rotary converters were operational. We passed a fan control panel, and he clarified that hot air would have been expelled from the basement through a wide duct at the building’s rear and out of its top.
Circling back towards the area with the overhead equipment, our guide, holding a device resembling a broom handle, demonstrated safety procedures. Irrespective of what the modern (or older) gauges indicated, a final manual check was always performed to ensure power was off in a work area. He extended the stick, creating a visible arc of sparks as it contacted a bare part of the equipment above. A collective “oooh” rippled through the group – a mix of thrill and appreciation for the logical precaution.
Next, we descended to the basement. Most opted for the narrow spiral staircase, perhaps for novelty or simply following the group, although a wider, straight staircase was also available.
Near the bottom of the stairs, our guide picked up several items from a cluttered table. These, he announced, were “hockey puck” diodes. I held one, surprised by its weight.
We listened as the guide explained the substation’s role in generating air pressure, which historically powered the subway’s signaling systems and train stop arms. He also recounted a familiar anecdote about the MTA’s 40-year agreement with ConEd for 25 Hz power to operate the subways. As the contract neared expiration in 1999, and with not all infrastructure modernized, the MTA urgently acquired frequency converters to avoid exorbitant fees from ConEd. Our guide narrated this story with suspense and flair, emphasizing how close the call had been.
We proceeded towards the back of the basement. The first room was filled with massive cables stretching from floor to ceiling, a tank-like object on wheels (possibly a fire suppression unit resembling a cannon), and dismantled wiring equipment.
Around the corner, we entered a parallel room. Our guide identified this as the “negative room,” explaining it was where power returned to the substation after completing a circuit. He mentioned the fascinatingly destructive potential of stray currents, noting they could erode bridges and sewer systems if not properly managed. He pointed out the return cables, notably insulated with oil.
Within the negative chamber, we continued our exploration. Moving back towards the stairs and the front of the building, we entered another room. This space, the guide explained, formerly contributed to providing commercial power to the surrounding area, reflecting the historical cooperation between power companies and subway systems.
In this room, large batteries were stacked along one wall. The guide detailed their role as backup power for the control system (as the substation is remotely managed from a power control center) and communication systems in case of power outages. This led him to recount his experience during the 2003 blackout – another familiar story, yet always engaging. As a superintendent at the time, he had just concluded a meeting with electric company executives when the lights went out!
It was time to return upstairs for a brief intermission before the walking tour segment of the day. Overcome by the heat, I was among the first to ascend the stairs.
I attempted to cool down during the break, alternating between the building’s interior and exterior, though neither offered much relief. Judging by the damp shirts, flushed faces, and ever-present water bottles, everyone was feeling the heat. Some participants took the opportunity to ask our guide individual questions.
Before we departed, the guide led us to a table we had passed at the tour’s beginning. Upon it lay lightbulbs and stacks of papers. He distributed the second set of papers, outlining the walking tour, and showed us the old carbon filament lightbulbs. These, he explained, served as indicator lights to synchronize the frequency of the rotary converters with the incoming electricity from the power station.
The guide then gave us a concise introduction to Thomas Edison and the dawn of electrification in New York. Edison acquired two buildings on Pearl Street and established a powerhouse, which began illuminating a section of the Financial District in 1882. This powerhouse used direct current and rapidly expanded from 59 to 500 customers within a year. Despite this triumph, it took Edison seven years to recoup his substantial initial investment.
With this historical context established, we were led outside, watching as the guide secured the substation building.
Our walking tour commenced eastward along Fulton Street, towards the Seaport. After a block, the guide halted us at an atrium-like building entrance. Here, he highlighted a plaque commemorating Edison and his Pearl Street powerhouse.
At the subsequent corner, we peered over construction barriers at ongoing utility work in the street. Though street noise made it difficult to hear the guide clearly, I assumed at least some of the work related to electrical infrastructure.
As we gathered closer, the guide shared his involvement in a project where steel-encased subway cables were being unearthed for replacement with cables in improved casings. During the excavation, he and his team unearthed some of Edison’s original feeder cables. Sections were donated to various museums, and the guide had brought a short piece to show us. The metal wires were insulated with rope, pitch, and beeswax, encased in a crumbling cast iron exterior. Without his explanation, the object’s historical significance would have been easily missed. It was fascinating to see and touch such a tangible piece of history.
Next, we proceeded down Pearl Street. We paused across from a moderately sized, mostly empty parking lot, dwarfed by towering buildings. This location, our guide announced, was the site of Edison’s power station. Operational only from 1882 to around 1895, the station suffered a major fire during its tenure, necessitating the replacement of much of the original equipment. The guide also shared anecdotes about Edison’s less admirable traits – a tendency to “borrow” and expand upon the inventions of others, including Nikola Tesla, when it served his profit motives.
Our next stop was the Excelsior Power Company Building, located north on Gold Street, a narrow alley-like street. This stately brick building featured a distinctive art deco sign and the year 1888. The company, our guide explained, provided power for arc lights – blue-tinted lamps primarily used for outdoor illumination. The building has since been converted into apartments. Here, our guide recounted the Great Blizzard of 1888, the pivotal event that prompted New York City to mandate the underground placement of all of Manhattan’s wiring.
Then, we walked south on William Street. Along the way, I captured images of the layered architecture above, a mix of old and new buildings. While I recognized some landmarks, navigating the Financial District’s winding, narrow streets remained somewhat challenging.
We turned onto Wall Street for our final stop. Across from the scaffolding-covered 23 Wall Street, Edison had famously demonstrated the electric lightbulb to Mr. J.P. Morgan. The story goes that Edison’s assistant, with synchronized watches, flipped a switch to illuminate the lightbulb precisely as a punchline to Edison’s presentation to Morgan.
By 1892, our guide concluded, Edison had exited the power industry, forced out in a merger. He continued his prolific inventive career afterward, focusing on other influential creations.
And with that, our tour concluded. I offered hasty farewells – driven by a desire for cold water, air conditioning, and lunch, in that order – and headed towards a subway station to fulfill those needs. My mind was buzzing with new knowledge, and my notebook filled with notes from a truly engaging and educational day. My only remaining wish was for a day that was ten or fifteen degrees cooler!
Explore the Cliff Street Substation walking tour route on this map.
