DPRK Donuts

I had a dream the other night that I was on a flight to Japan - a regular, scheduled commercial aviation flight. We had engine trouble, though, and due to the reduction in thrust, we were diverted...to North Korea.

Either I was coming from somewhere in central Asia, or my subconscious has a poor grasp of geography.

Anyway, following a safe landing at an unnamed North Korean airport, the other passengers and I were allowed to roam around the terminal until an aircraft became available to take us the rest of the way to Japan. At this point, I discovered that there was a Dunkin' Donuts in the terminal. I invited a few other passengers to sample its fare with me. I called it DPRK Donuts, which my subconscious thought was hilarious.

The donuts were acceptable. Better, though, was the box, which was covered in propaganda. We folded it up to take home, barely stifling our laughter in front of the very serious-looking donut man.

I think I need professional help. With chocolate frosting and sprinkles.

233 S. Wacker

This building has been in the news twice recently. The tallest building in the world from 1973 to 1998, and currently the tallest skyscraper in North America, the building formerly known as the Sears Tower was recently renamed for some holding company. Many Chicagoans will forever refer to it by its original and proper name. I don't want to live in the past, so I'll just call it 233 South Wacker Drive.

Less infuriatingly, four glass "skyboxes" which peek four feet outside the walls of the 103rd-floor observation deck were added in January 2009. I had a chance to hear one of the project engineers speak tonight. He began his presentation with a picture of Ferris Bueller and friends with their foreheads pressed up against the windows so they could look straight down. The purpose of adding the skyboxes was to enable users to to get Ferris's view without getting forehead prints on the glass. Now, glass-bottom observation ports on tall structures are nothing new - the CN tower has 'em, for example - but the skyboxes at 233 S. Wacker are unique in that (1) they have no steel in the sight lines, and (2) they are retractable. Amazing! The glass floor is hung from an overhead steel frame by the glass walls alone! And, AND, it was a design requirement that the skyboxes retract to be flush with the rest of the outer walls such that they wouldn't interfere with normal operation of the building's automated window washing equipment.

Here you can see the one of the boxes from another box. All four boxes are on the western wall of the building. The steel tubes from which the box hangs are plainly visible at the top of the box.











The boxes deliver on the promised straight-down Ferris Bueller view, as shown below. Those are my feet there, with nothing but three panes of glass and 103 stories of air between them and Wacker Drive.

Finally, just for fun, a picture of downtown (looking north) and a long-exposure shot of the view to the northwest, including traffic on the Kennedy Expressway.

Do not poke the rattlesnake

In June 2005, I had a run-in with a snake at one of my favorite places: the dells of the Wolf River in Menominee County, Wisconsin. Slithering about on the billion-year-old Wolf River basalts was this fellow:

The snake then coiled up and began to shake its tail in the underbrush, making a rattling sound. This got my attention, and I took several steps back to establish and more respectful distance. For the next five years or so, I bragged to my friends that I had stared down a rattlesnake.

In a recent visit to the Henry Vilas Zoo in Madison, Wisconsin, I learned that there are two species of rattlesnake in Wisconsin, and neither occurs anywhere near Menominee County, highlighted in blue on the maps below (range maps photographed at the Vilas Zoo).

This was confusing - I heard the snake rattle! I was traveling Lisa and her parents, so I had to come up with an explanation quickly. The answer came from the kids' section of the Wisconsin Dept. of Natural Resources web site - that's right, the kids' section. Turns out there are at least two non-venomous Wisconsin snakes that twitch their tails in the leaf litter to imitate a rattlesnake: the fox snake (Elaphe vulpina, also known as the pine snake) and the rare bull snake (Pituophis melanoleucus). Humbled!

When I got home, I checked the WDNR's excellent pamphlet, Snakes of Wisconsin, and determined that the handsome reptile in question was in fact a fox snake. The orange head is the giveaway. I'm no biologist, but I think being slightly out of focus is also a characteristic of the species.



While I hadn't faced a hyper-venomous death-serpent, I still consider myself lucky to have experienced this encounter with the herpetofauna of the Badger State. Meanwhile, I'm pleased to announce that I recently did stare down a timber rattlesnake (Crotalus horridus)...


...but this one was behind glass at the Vilas Zoo's reptile house. I'll close with some helpful advice from the good folks at the zoo:

Prufrock

Let us go then, you and I,
To a deluxe apartment in the sky.

-T.S. Eliot meets The Jeffersons

SD-FO ought to STFU

The next person who mentions the terms "structurally deficient" or "functionally obsolete" in my hearing will be punched in the mouth.

From talking heads on cable news to engineers and policymakers who really ought to know better, misuse of these terms has been rampant since at least August 2007. Let's set things straight with a healthy dose of facts and the not-so-subtle threat of violence.

Structurally deficient (SD) means that load-carrying elements of the bridge have been rated as "poor" or worse (4 or below on the National Bridge Inspection Standards scale of 0-9, where nine is brand-new and zero means the bridge has fallen into the river) or that the waterway opening provided by the bridge is inadequate¹.

Functionally obsolete (FO) means the bridge is inadequate from the perspective of roadway geometry issues¹ (traffic capacity, roadway shoulder width, and approach sight lines, for example).

Let's examine the abuse of these terms in detail:

First, and most importantly, SD and FO are planning, not structural engineering, terms. They do not necessarily reflect the safety or serviceability of a bridge. Bridges designated as SD or FO get higher priority for repair and rehabilitation. As a consequence of this, it can actually be good for a county engineer to have a bridge designated SD or FO - state or federal money may then become available.

Structurally deficient is not a synonym for "unsafe" or "near collapse." Recall that the SD designation is based upon a load-carrying element being rated 4 or below on the National Bridge Inspection Standards (NBIS) scale. 4 is basically the lowest rating at which an element can be left in place as-is. You have probably driven over a bridge with an element rated 4 within the last seven days. That doesn't mean your life was in danger.

Reporting the sum of SD and FO bridges is especially meaningless from a bridge safety perspective. I can't tell you how many presentations I've attended where the first words from the speaker's mouth were "Since X percent of the nation's bridges are structurally deficient or functionally obsolete..." - from a safety perspective, this is about as meaningful as saying "X percent of the nation's bridges are painted green." FO has absolutely no structural safety meaning. A bridge can be rated FO because its shoulders are too narrow, or because it has an old-style guardrail. That doesn't mean the bridge is going to fall down. One very common cause of an FO designation is that traffic has increased on the route carried by the bridge. A bridge can be deemed FO even if it has a good structural rating of 7, 8, or 9. So, while FO bridges ought to be upgraded or replaced to maintain good levels of service throughout the network, an FO designation doesn't provide any more indication of a bridge's safety or serviceability than the color of the bridge paint. If you're trying to make a point about structural capacity, don't inflate your numbers by counting FO bridges too.

The federal definition of a "bridge" is any structure with a clear span of at least 20 feet². That includes everything from the Golden Gate Bridge down to structures that are little more than oversized culverts. The SD and FO criteria may be applied to any structure in this spectrum. When we refer to the number of SD/FO bridges, an outdated bridge on a low-volume county road counts the same as the heavily traveled (and both SD and FO) Milton-Madison (Kentucky/Indiana) Bridge, a regionally important Ohio River crossing which, if out of service, necessitates a detour of 55 miles. Of the 600,000 or so bridges in the United States, the vast majority are "boring" bridges with relatively short spans and lots of built-in redundancy. That means that even if a structural member is deteriorated, there is still enough load capacity too keep the bridge in service.

Bridge collapses are shocking in part because they're so rare. Regular inspections in keeping with the National Bridge Inspection Standards help keep them that way. Yes, we should be sure that bridge maintenance and inspection is adequately funded; yes, research into improved methods for structure evaluation and testing should continue - but there's no reason to panic over big numbers with scary-sounding sames that ultimately have little meaning from a safety perspective.

---

^1. Federal Highway Administration: Bridge System Conditions - Explanation of Bridge Deficiencies

^2. United States Code: 23 CFR 650.305 (2009).

Flags: District of Columbia

I am pleased to write about a flag that is doubly special: (1) it is the flag not of a state of the Union, but the Federal District, and (2) I am currently in this District. I love when my travel schedule aligns with my geographic nerdosity.

The authorization for a special federal district, not to be a part of any state, as the seat of national government was laid out in Article I, Section 8 of the Constitution, which grants the Congress authority

To exercise exclusive Legislation in all Cases whatsoever, over such District (not exceeding ten Miles square) as may, by Cession of particular States, and the acceptance of Congress, become the Seat of the Government of the United States, and to exercise like Authority over all Places purchased by the Consent of the Legislature of the State in which the Same shall be, for the Erection of Forts, Magazines, Arsenals, dock-Yards, and other needful Buildings;

Conveniently, the Constitution now spends most of its time in "such District." Now, I once thought that the creation of the Federal District was mandated by the Constitution, but the excerpt above suggests that Congress was allowed, but not required, to establish a seat of federal government distinct from any state. Anyway, the Federal District was established along the Potomac River, on land ceded from Maryland and Virginia - though Virginia got its cession back in 1846. Until then, the District of Columbia had been divided into two counties: the county of Washington on the north bank, and the county of Arlington on the south. Similarly, there were multiple municipalities in the District: until 1871, letters could be properly addressed to Georgetown, DC. The Organic Act of 1871 unified the City of Georgetown, the City of Washington, and the County of Washington into a single legal entity, the District of Columbia.

So, while DC as we know it came into existence in 1871, it wasn't until 1938 that it adopted its spiffy red-and-white flag. The banner is based on the three stars and stripes from the shield on George Washington's family coat of arms. I heartily approve - it is instantly recognizable, and simple enough for schoolchildren to draw. The citizens of the Federal City seem to dig it - it appears on non-governmental logos and is flown from non-governmental buildings throughout the District.

The official motto of the District - Justitia omnibus ("Justice for all") - and the license plate slogan, "Taxation Without Representation," are not-so-subtle digs at the governance of the Federal City. Citizens of DC have a non-voting delegate in the House of Representatives, and only won the right to vote in presidential elections in 1961, with the ratification of the 23rd Amendment to the Constitution (they didn't actually get to vote until the presidential election in 1964).

As far as I can tell, the selection of the wood thrush (Hylocichla mustelina) as the official bird, or the scarlet oak as the official tree, of the District carries no specific political message. Too bad.

Be brave, like prawn

Menu boy no be coward, like shrimp; menu boy be brave, like prawn.
-The Simpsons, Episode CABF01, "Lisa the Tree Hugger"

I took a picture of this giant freshwater prawn (Macrobrachium rosenbergii) at the Smithsonian National Zoo in Washington, DC, specifically so I could make a motivational poster for Lisa. Having completed my mission, I'm now filled with rage - it turns out that Macrobrachium and many other so-called "prawns" are not true prawns at all: they are freshwater shrimp. Some helpful Australians have provided clarification:

...there is one sure way to tell them apart. In shrimps or carideans the side plate of the second segment of the abdomen overlaps the segments in front and behind. Prawns, most of which belong to the family Penaeidae of the group Dendrobranchiata, have all the abdominal side plates overlapping tile-like from the front. A more fundamental difference but one impossible to appreciate in a single specimen is that female prawns do not brood eggs but shed them into the currents where they develop independently. It would therefore make sense to call all member s of the Penaeidae "prawns" and members of the Caridean "shrimps" and this is what most Australians do....Confusion arises when we hear Americans refer to prawns as "shrimp".

So that settles questions of anatomy, but not courage. Is there any relationship between location of abdominal segmants and strength of character? I leave that to the decapod philosophers.