Monday, August 15, 2011

The Stanton "Covered" Bridge


The Stanton "Covered" Bridge
 It's understandable if the title of this post may be a bit confusing in a couple of different ways. First, you might be saying, "I've never heard of a covered bridge in Stanton." Secondly, you might be asking, "What's the deal with the quotes around "covered"?" As it so happens, both of these items are connected, and they led me on a journey to what I think is a very interesting lost bit of local history. Then, as a bonus, the answers I found helped me make sense of another picture that had kind of bugged me for a while now. And in the process, I was exposed to a type of structure that I didn't even know existed, let alone existed right here in our area.

My guide on this journey was Will Truax, a bridgewright from New England (here's his blog) who repairs, restores, and rebuilds covered bridges for a living. His expertise was crucial in figuring out just what it was I was looking at in the picture above, sent to me by Ken Copeland. At first, I thought it might be the railroad bridge mentioned in the Stanton Station post (also spurred by a photo from Ken), but Will assured me that this was definitely not a railroad bridge. Instead, this was a type of bridge that was not uncommon at one time in the 19th Century, but because of its lack of durability, is almost unknown today. This bridge was what is known as a Boxed Pony Truss, and this one specifically was a Queen Post type. It spanned White Clay Creek southwest of Stanton, where the concrete arched bridge is now. In fact, I believe the picture of the Boxed Pony bridge was taken from that spot of land between Mill Creek (to the right in the picture below) and White Clay Creek -- just about where today's Route 7 passes overhead.


This type of bridge, the boxed pony truss, is what I'd describe as a semi-covered bridge. As noted in a previous post, the purpose behind covering a bridge is to protect the timbers of its wooden frame from the elements, thereby greatly extending its lifespan. Usually, in a classical covered bridge, this is done by covering the entire bridge with siding and a roof across the entire span. However, doing that was rather expensive. Another option was to only cover, or box, the trusses (the support structures on either side). This was done by cladding them in siding, and placing a small roof-ette over top. In the top picture, if you look closely at the left side of the "V" in the middle, you can see a bit of the roof-ette of the far truss. This method could be used on pony truss bridges which, unlike through trusses, have no overhead connecting structures between the two sides.

The queen post designation refers to the truss design, which gives the bridge what I call an "up-across-down" look. The Stanton bridge in particular was a two span structure, which was apparently not very common. As stated, the main reason for building a boxed pony as opposed to a "true" covered bridge was financial. Although fully covering the bridge would extend the life of the support timbers beneath the road deck, it was significantly more costly to do so. Even in a "true" covered bridge, the flooring itself would occasionally have to be replaced, but the support timbers below would require less frequent inspection and replacement. It really seems to be a decision about upfront construction costs as compared to longterm maintenance costs. Those longterm costs appear to eventually have caught up with most of the 19th Century boxed pony bridges -- there are only a relative handful of them in existence today.

The 1904 Steel Truss bridge, shown in 1921
Records indicate that the end came for the Stanton boxed pony bridge in 1904, when it was replaced with a 102' long steel truss bridge, shown above. This bridge stood for 38 years, until it was replaced by the concrete rainbow arch bridge we see today. This link here has more information about the concrete bridge, including the fact that it was the first, and maybe only, one of its type in the state. Now, of course, it is used only for pedestrian traffic, having been bypassed by the new, elevated section of Route 7 in the late 1980's.

While researching and thinking about the Stanton bridge, I happened to recall another picture of a bridge that I had seen, but couldn't make complete sense out of. It came from the same place as the picture of the Stanton steel truss bridge -- a 1921 inventory of New Castle County bridges conducted by the State Highway Department. The only information attached to the shot was that it was "Near St. James Church". In looking at it, I had always thought that it kind of looked like a very short, oddly shaped covered bridge. After learning about boxed pony bridges, and after consulting again with Will Truax, the Official Bridge Consultant of the Mill Creek Hundred History Blog (now there's something for his resume), I now know I was mostly right.

This bridge, which I believe spanned Mill Creek on Old Capitol Trail (near where Telegraph Road merges with it) is also a boxed pony truss bridge. It's a different style of truss, but still a boxed pony. This page has pictures of a similar bridge in Pennsylvania, to give you a better idea of what it might have looked like. The only clue to its construction date is this mention in the "Journal of the House of Representatives of the State of Delaware" which shows an appropriation in 1858 of $375 for "Rebuilding bridge over Mill Creek above Stanton". It's very possible that this refers to this bridge. I don't know when this bridge was replaced, but it seems that at one time, the Stanton area was a relative hotbed for this almost-vanished type of bridge, the boxed pony truss.

Additional Facts and Related Thoughts:
  • Here is a link to the DELDOT page that contains the 1921 bridge inventory mentioned in the post. There are also some old annual reports that have some interesting pictures, too. A lot of cool stuff, if you have the time to go through it.

23 comments:

  1. Speaking of St. James Church, didn't the road where that church is located at one time continue north across Kirkwood Highway (next to Kirkwood Auto) and end at Milltown Road (next to Village of Lindell)? If so, it would have crossed Mill Creek & required yet another bridge.

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  2. Thanks for the honorable mention, and I was glad to help!

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  3. Yes, St. James Church Rd, which is now two unconnected streets, was once one road. And you are correct, it did cross Mill Creek, somewhere behind Oakwood Valley Swim Club, which is behind Kirkwood Auto. If the bridge was not where I thought it was, then this would be the next logical place. Frustratingly, in the 1921 inventory there are several bridges listed as being "Near St. James Church", but its hard to tell exactly where they were. If I ever come across anything more that points to one place or the other, I'll update the post.

    On a related note, I've also added a link to the DELDOT page that has the bridge inventory pics, as well as other old highway pictures. Lots of cool stuff, if you have the time to wade through it.

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  4. I know where the bridge over Mill Creek connected those now unconnected parts of St. James Church Road. There's an ancient foundation on the east bank of Mill Creek behind Bailey Drive in Limestone Acres. In the mid 1960s when I was there almost daily on after-school fishing excursions there was a large wooden timber; there were also iron parts, large bolts, etc. When the west side was still a dairy farm, the ramp leading to the bridge from the west bank was clearly visible as a hump in the meadow at the edge of the creek. I don't know whether that feature remains, but I'm sure something is left on the east bank. Perhaps the timber is still there. In my memory it is pretty high up away from the water. Traces hold clues about the bridge construction. Now my curiosity is piqued. It's an hour from where I live in Lancaster...I'm mentally clearing out this Saturday afternoon for a reprise excursion to my old haunts.

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    1. Bill -- I'm about 55 minutes closer. Let me know if you're going exploring.

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    2. 2:00 p.m. Saturday, meet you at the bridge over Mill Creek on old Limestone Road at the Harlan Mill. I'll be the one with the red baseball cap. I'd like to have a look there after reading some of these interesting posts. Then there is my "springhouse" about 200 yards to the south. Something was there. I have a hunch that the area contains a pretty serious legacy sediment, because there were vertical banks of Millcreek approaching 5' in places. That seems to speak of a millpond. The historical map at the top shows the millpond immediately below the bridge where we're meeting; and is that a millrace going from that pond to the Cannon mill site at Lindell? Really looking forward to meeting you, Scott. Wading boots and expecting to bushwhack some spots.

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    3. Bill & Scott, I am looking forward to hearing about this expedition. Donna P.

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    4. Scott and Bill-

      Mind if I join you on Saturday? My MIL lives in Limestone Acres and I have walked the area around the old Harlan Mill a few times. I'd like to get another perspcetiv on what I think I see.there.

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    5. Bill, I would like you to join in...

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    6. Any chance we could do it slightly earlier? Maybe 1 or 1:30? I have a family obligation later in the afternoon and would probably have to cut out about 3. Or make the wife mad. So, out about 3. Yes, I think you're right about the mill race, Bill.

      Bill Harris -- Fine with me. I think the more eyes and minds the better.

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    7. Great, I'll see you then.

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    8. one last thought. we still have snow cover in Lancaster. Although one of you would probably have mentioned it if our target area still had cover, thought I'd check. It would kind of dampen observations if there was snow on the ground

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    9. No, we're pretty clear here. Only a little here and there where it had been plowed. We should be good.

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    10. That was an interesting 2 hour trek with Scott Palmer and Bill Harris as we walked, observed and talked from the Chandler mill downstream to the crossing of St James Church Road on Mill Creek. Springing snowdrops alone made the trip worthwhile. Questions were raised. A square opening under the Limestone Road bridge abutment: a gate for the millrace? What lies under the large mass of fill deposited south of the Chandler mill in mid-20th century that might give clues hinted at by the surviving springhouse remains? The siting of the mill dam immediately downstream from the Chandler house? Track of the headrace from millpond to Cannon mill. Location of the Cannon mill; a tantalizing undeveloped patch in Lindell Farms invites further investigation. The biggest question of the day for me was, why the St James Church Rd bridge over Mill creek, when alternate routing was available via Milltown Road?
      As to the bridge remains, it was disappointing to see the amount of erosion; hoping for too much to expect more than a well weathered mound. No doubt the volume of water in the stream bed during large rain events has increased with the suburbanization upstream.
      Maybe another trek is in the future, approaching the site from St James Church, across Kirkwood highway and past the swim club...

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    11. Good write-up, Bill, thanks. It was a fun, thought and question filled walk. There are definitely a few things that deserve a closer look.

      As to St. James Church Road, in looking back at the maps something jumped out at me. As we mentioned, the 1849 map doesn't show the extention of the road at all north of what's now SJCR and Old Capital Trail, by the church. 1868 shows it as a dotted line, which usually means a private lane or small road. One other thing shows up for the first time on the 1868 also -- the Dist. 35 School. It's just west of the Cannon (later Lindell) House on what's still called SJCR. The 1881 and 1893 maps show the northern part of the road as a solid, normal road.

      I wonder if the building of the school and easier access to it had anything to do with the road and the bridge?

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    12. Where are the photos ??? We wanna see too.

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    13. I only took a few of the Harlan Mill and Chandler House. Maybe I'll head back over this weekend and take a look at what I think was the site of the Cannon Mill (Lindell property). From there I can take some shots across the creek to where we think the road went across, but there's really not much there. Could get a shot of the drainage culvert under the bridge on Old Milltown, but I think that might have just been for general drainage. More I think about it, I don't think it is old enough to have anything to do with the mill or a mill race.

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    14. Yes, I agree Scott, the extant ditch just south of the Harlan mill is probably a recent run from the culvert under Limestone Road. My memory of it even pre 1964 when Limestone Road was widened is consistent, bc the old Limestone Road would have needed something there as well.
      But, something else from the map. The millrace going past Harlan mill goes well beyond the mill to the bottom of the adjacent pond; to me that looks like the tail race re-entered Mill Creek somewhere below the dam for the pond that backed up to the Milltown Road bridge. I don't know how accurate or scaled the map is, but it definitely shows what I think may be the tail race of Harlan mill extending to a point below the adjacent millpond. That makes sense because of the low exit of the water at Harlan's wheel. Enabling a maximum head for power generation brings the spent water out of the wheel below the level of the pond right outside the door. You can increase your available power by lowering the outfall of the water; lower the tailrace, increase the power for a given elevation of the mill. Hence the necessity for a long tailrace returning the water to a lower elevation at the creek i.e. below the dam. Remember the ditch I pointed out at the swamp running perpendicular into Mill Creek? It is definitely man-made and ancient, and randomly placed with regard to any modern structure, it's kind of in the middle of nowhere now. But if the original millpond dam was in approximately the location we surmised, near the more recent pool-filling dam, then that ditch makes sense as the end of the tail race from Harlan, returning the water to Mill Creek just below that dam.
      It's interesting that the pond serving Cannon was way upstream next to Harlan , while Harlan's source of water was far upstream at a yet higher millpond. The design maximizes utilization of the fall of the creek--you get a certain amount of power from a given quantity of water at a given head. It's a tribute to the engineering skill of the builders. They were packing things in along Mill Creek, using every bit of available power along a significant stretch of the creek. I think this technology had been pretty well worked out in Europe; Yankee ingenuity adapted it to the conditions in the new world. It's left to us to look back in admiration, puzzling things out, renewing our wonder at their intelligence and skill.

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    15. Scott, I think the Cannon mill site was higher up away from the creek. First because it is depicted such on the map above, with the millrace pretty far away from the creek where it intersects the mill. A siting up away from the creek could be expected in terms of the above discussion of preserving the head of water in the millrace; since the creek is falling between the mill pond and Cannon site, following an isocline to preserve the head in the millrace would require that the race move "further up the bank" as it goes downstream toward the water wheel. My money is on the mill siting somewhere around the preserved homestead and barn.
      Related to this you mentioned a mill race that actually had a viaduct to carry it over a run, was it Calf Run? All this marvelous engineering to conserve the elevation of the water in the race. If I get back to Mill Creek as I want to on Saturday, I'm going to start at the swim club, walking west and looking for evidence of the tail race entering the creek on the west bank. Unfortunately, it looks like Lindell construction is almost to the creek. Here's hoping for some untrammeled wilderness in that narrow slice of trees.

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  5. Some friends and I drove over the cement pedestrian bridge in 2008 just being dumb. We thought we were going to die, probably a bad idea. Came out in the grass of happy harrys parking lot..

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    1. It's really a cool looking and kind of historic bridge. It's a shame something can't be done to spruce it up and make it somehow useful and nice.

      And to the comment below, ouch. I've found that booze goes great with a great many things. Heights is not one of them.

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  6. I went to high school with a kid who was drunk and climbed to the top of the cement pedestrian bridge one night and accidentally fell off. The river only being a few feet deep he became became permanently paralyzed

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