Oversize Load

Old buildings are on the move in northern Vermont. Last Sunday, a 19th-century house was transported 2 miles by truck, on flatbed trailers, from Winooski to Burlington. The following day, during an unrelated project in the Northeast Kingdom, a similar feat was performed using oxen.

Bridport-based New England Building Movers managed the job in Burlington. They moved the private home basically in one piece; only the dormer window was removed. The route included crossing the Route 7 Winooski Bridge (I envy the engineer who got to analyze this load case), and power lines and traffic lights were swung out of the way as necessary. Compared to the self-propelled modular transporters used for rapid bridge replacements, this convoy traveled at a surprisingly quick walking speed of about 3 mph. I guarantee the Burlington Free Press video of a house rolling down the street will make you giggle.

Developer Nate Dagesse plans to build housing and offices on the now-vacant site in Winooski. He gave away the structure for free; the new homeowner, Chris Khamnei, needed only to pay the cost of moving it. I wonder if the $100,000 price tag includes construction of a new foundation… although even if the foundation cost another $100K, it’s a bargain compared to building a similar-size house from scratch. Add a hefty savings in embodied energy – new construction materials were minimized, and old ones didn’t go to a landfill – and moving a house looks like a very smart thing to do.


Oxen move a historic Brownington structure the old-fashioned way.

Not to be outdone, East Montpelier-based Messier House Moving & Construction moved a Brownington schoolhouse a third of a mile using 44 oxen. The choice of power was historically driven: draft animals moved structures frequently in 19th-century Vermont, including this very schoolhouse. (Town officials say this building, formerly the Orleans County Grammar School, was simply returned to its original location.) Messier began the project by excavating around the schoolhouse and inserting steel support beams under the structure, then using jacks to lift it. That’s exactly how the same company lifted a house I worked on last summer. Working with beasts of burden was new to them, however.

Thanks to Laura Schutz for both stories!

Tiny Tuesday: The Tiny Washer

Recently, several friends have shared a viral-style video about a foot-powered washing machine. Of course I was intrigued. Even an ENERGY STAR certified washer uses about 280 kWh of electricity and 13 gallons of water per load. How much can a human-powered model save?

A lot, it turns out. The YiREGO Drumi holds 5 pounds of clothing and uses 2.3 gallons of water per load. You start by putting in your clothes, half the water, and detergent, and then you pump the foot pedal for five minutes to swish it around. Next you drain the machine, add the rest of the water, and pump the foot pedal for another five minutes to rinse. The company claims it has about half the capacity of a typical electric washer. (I find this claim slightly inflated – 5 pounds equals about two warm-weather outfits for me, which means I’d have to do four or five loads with the Drumi to match my current washer.) The ten-minute ankle workout is a nice bonus.

Unfortunately, I can’t find any reviews, so I don’t know how well the Drumi does its job compared to a traditional washer, or how reliable it is over many years of use. And you might still need a dryer, which is a far larger energy suck averaging 769 kWh. (Of course, for a lot of laundry, the old fashioned clothesline works just fine.)

Several other small washers exist on the market. A few years ago Kent Griswold’s Tiny House Blog reviewed a hand-crank tabletop washer, which is sold by various companies such as The Laundry Alternative. You can also buy a variety of plug-in portable washers, often with sink faucet adaptors, which might be more convenient than human-powered models but don’t save much energy over full-size washers.

Indeed, the most appealing thing about the Drumi (and its ilk) is the size. Slightly larger than a five-gallon bucket, it’s very appealing for anyone living in a small house or apartment with no electric washer. Sure beats a trip to the laundromat!

Figures from YiREGO and energystar.gov.

Monthly Mechanics: Beam Bridges

I designed bridges for the first five years of my career, and to me they remain some of the purest feats of civil engineering. A bridge has no unnecessary parts – every bit contributes to the structure, stability, and safety. (Most architects will argue that a well-designed building also has no unnecessary parts. But engineers do most of the design work on a bridge whereas architects do on a building, so everybody is biased.)

Three types of bridges are particularly interesting because they mimic structures that occur in nature: beam bridges, arch bridges, and suspension bridges. I’ll address these types one article at a time.


The world’s oldest bridge? (flickr – creative commons)

Beams are possibly the oldest bridges ever used by people (think a log over a stream), and by far the most numerous today. They comprise most of the bridges that you drive/walk/ride over and under every day, the ones you barely notice. Look closer, though, and you’ll see no two bridges are quite the same.

For starters, there are an astounding number of different beams. They might be made of steel, concrete, or (not so often nowadays) wood. Steel beams range from smallish I-beams to huge girders built up from steel plates. Concrete beams might be I-shaped or T-shaped, or they might be box girders so wide that a single piece holds the entire roadway. (Fun fact: box girders are hollow, and bridge inspectors go inside with flashlights to check the condition a couple times a year.) Timber beams are sometimes just that – single timbers – and sometimes glued laminated lumber built up from many thin pieces of wood to form something larger and stronger.

Or maybe it’s the configuration of the beams that varies – how frequently they are spaced, whether they are continuous over several spans or terminate at each pier, whether smaller beams support the bridge deck by running perpendicular over the main ones. When an engineering firm begins a new bridge project, it will often submit a type study, presenting the client with many bridge options. The options may differ in their ease of design, ease of construction, ease of repair, aesthetics, and cost.

One of my favorite technologies is the self-propelled modular transporter, or SPMT, which enables a beam bridge superstructure to be replaced in a weekend. A new bridge is constructed next to the old one and placed on an SPMT; then, when the old bridge is demolished, the new bridge can simply roll into place. Watch this timelapse of an SPMT bridge replacement I worked on in Boston.

Next time you travel through a highway underpass, look up – you’ll surely see something you never noticed before.