Ethan Grossman: What goes up, must come down
A series of stories that borrow from daily life experiences to illustrate engineering concepts.
Elevators go up and down, that much we know. One could say that they follow the common saying: “What goes up must come down.” I researched the origins of this saying, and surprise, surprise, Isaac Newton once again gets credit for stating the obvious. The fact that Newton receives credit for such an observation gives me hope that any of us can be elevated to levels of genius by stating other such obviousness. “Water is wet,” for example, or “Ice cream tastes good on a hot summer day.”
Something that has not been obvious to me is the application of building, life safety and plumbing codes as they relate to elevators. Over the course of my career, the requirements for plumbing and fire protection as they relate to elevators have gone up and down, enough to make my head bobble.
The idea to write about elevators came from my colleague, Fred Thomas, who works at C3 here in Boston. We ran into each other at the annual ASPE product show our local chapter holds. I recommend going to chapter meetings and events for any type of organization that your work focuses on. It offers opportunities to discuss topics nobody else in your social circle would want to talk about, such as sump pumps in elevator pits.
Fred reminded me of the changes to our building code. We had a discussion about why elevator sump pumps were important, and he told me about a tragedy in Houston where a woman drowned because she was trapped in an elevator that had been “called” down to the lowest floor.
Fred and I proceeded to discuss everything we knew about elevators and the plumbing and fire protection design considerations related to them — pumps that detect oil, where to pump the discharge: clear water or sanitary, types of elevators: traction and hydraulic, oil interceptors, sprinkler protection, elevator machine rooms, shunt-trip, etc. The list of things to consider was enough to cause a “brain cramp” as I call it.
I recalled one job I worked on in Rhode Island where the Certificate of Occupancy was held up because the elevator and fire AHJs disagreed about sprinklers in the shafts. Life safety devices are sometimes tied into the power for the elevator through a “shunt-trip.” If power to the elevator is discontinued prematurely, it may hinder the ability of first responders to save lives. Fred and I left our conversation to go browse the product show floor. I was glad he shared some of his experience with me on the recent jobs he had worked on.
Here in Massachusetts, the Commonwealth had omitted the requirement for elevator sump pumps about 15 years ago. The state had also omitted sprinklers at the top of elevator shafts and in the pits as well. I was taught to design with their inclusion at the beginning of my career in plumbing engineering. When the code changed, around 2006, we were instructed to leave both sprinklers and pumps out. As recent as last year, the codes changed back to require pumps (or drains).
For many of you reading, the requirements for pit drainage, by pump or gravity, as well as the requirement for sprinklers hasn’t changed, and you’ve been doing it one way all along. I look forward to hearing your experiences with some of the jobs you’ve worked on.
An integrated design approach
Engineers and designers are responsible for understanding the technical applications of building components and when to include them based on codes. The example I gave of the building in Rhode Island was likely indicative of a conflict in the codes that were adopted at the time. I’m sure all the authorities were just trying to follow their own rules. I try to be cooperative and understand what is required by code while meeting the owner’s expectations. I like to say, “If someone wants a purple water closet, specify a purple water closet.” There isn’t any rule against it that I’m aware of.
This is not a new topic that just popped up out of nowhere. In my research, I found an article published in PM Engineer from March 2002, where the author discusses this very topic. I think the author says it best: “It is recommended that an integrated design approach should be taken, with all building trades people and building officials made aware of the design decisions. The design of the elevator requires a coordinated effort. Everyone must be sensitive to each other’s needs and requirements. In the end, a successful system and a pleased owner will be the result.”
If you happen to be an engineer in Massachusetts or some other state where elevator sump pumps are new to you, start out by asking what type of elevator is being installed. You’ll soon find out that the design solution may not be a simple open and close case. Stay curious and look to those who’ve been on this elevator ride before.
If you have fond memories of playing on see-saws as a kid or bopping around the neighborhood on a pogo stick, you may want to consider becoming an expert in elevator code analysis. Join an NFPA committee related to elevator control and protection such as NFPA 72 or NFPA 13. Get involved with ASPE; either your local chapter or on a national level. The topic of elevator drainage and protection has both technical and legislative aspects. Become familiar with ASME A17.1, the Handbook on Safety Code for Elevators and Escalators.
These are all suggestions to either help develop your career or to have you help others learn from your years of experience. Designing plumbing and fire protection systems for elevators may seem as simple as a ball bouncing up and down, but my experience has shown the changes in codes over the years and the varying interpretations by different jurisdictions can make the task more like chasing a moving target.