# Why does this bridge have two holes in its brick walls? **URL:** \ **Category:** Factual Questions\ **Created:** [November 6, 2014, 1:05am UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828 "2014-11-06T01:05:25Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [November 6, 2014, 1:05am UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/1 "2014-11-06T01:05:25Z")
Here’s a bridge I drive across occasionally: [A bridge in New Jersey](https://www.google.com/maps/search/98+County+Rte+672/@40.1555667,-74.6478628,3a,75y,271.12h,60.04t/data=!3m4!1e1!3m2!1sjblOKsARTYhSil5HujhjXA!2e0) Why are those holes there? ---
**Author:** ![Artemis\_Tardis](https://avatars.discourse-cdn.com/v4/letter/a/4bbf92/32.png) [@Artemis\_Tardis](https://boards.straightdope.com/u/Artemis_Tardis)\ **Post date:** [November 6, 2014, 1:19am UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/2 "2014-11-06T01:19:34Z")
Might be saying something stupid, but it looks like the bridge is lower than the roads leading to it. So it could be something to avoid flooding on the bridge in case of a lot of rain… ---
**Author:** ![CraterLayer](https://avatars.discourse-cdn.com/v4/letter/c/87869e/32.png) [@CraterLayer](https://boards.straightdope.com/u/CraterLayer)\ **Post date:** [November 6, 2014, 1:30am UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/3 "2014-11-06T01:30:12Z")
They look to be on each side of the expansion joint in the middle of the bridge. No doubt related, but no guess why, 'cept maybe New Jersey? ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [November 6, 2014, 1:37am UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/4 "2014-11-06T01:37:52Z")
> [@Artemis\_Tardis](#): > > Might be saying something stupid, but it looks like the bridge is lower than the roads leading to it. So it could be something to avoid flooding on the bridge in case of a lot of rain… The same thought crossed my mind, but wouldn’t drain holes be lower? If you rotate the picture to the other side of the bridge you can see the surface of the water below it and it’s not really near the bottom of the bridge, so I see no reason to place drain holes so high. ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [November 6, 2014, 1:51am UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/5 "2014-11-06T01:51:48Z")
Maybe weep holes? > **[Crying](https://en.wikipedia.org/wiki/Weep)** > > Crying is the dropping of tears (or welling of tears in the eyes) in response to an emotional state or physical pain. Emotions that can lead to crying include sadness, anger, joy, and fear. Crying can also be caused by relief from a period of stress or anxiety, or as an empathetic response. The act of crying has been defined as "a complex secretomotor phenomenon characterized by the shedding of tears from the lacrimal apparatus, without any irritation of the ocular structures", instead, givi... > [@](#): > > A weep, a weep hole, or a weep-brick is a small opening that allows water to drain from within an assembly. Weeps are located at the bottom of the object to allow for drainage; the weep hole must be sized adequately to overcome surface tension. > > Weeps may also be necessary in a retaining wall, so water can escape from the retained earth, thus lessening the hydrostatic load on the wall and preventing moisture damage from freeze/thaw cycles. In such cases the weeps consist of small-diameter plastic, clay or metal pipes extending through the wall to a layer of porous backfill. That doesn’t seem to quite fit, because the holes aren’t at the bottom and those walls don’t appear to be retaining anything. ---
**Author:** ![Lukeinva](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lukeinva/32/17872_2.png) [@Lukeinva](https://boards.straightdope.com/u/Lukeinva)\ **Post date:** [November 6, 2014, 2:23am UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/6 "2014-11-06T02:23:27Z")
Possibly at one time that bridge was a draw bridge, and the holes held some kind of draw bridge part. There is a clear separation in the bricks that are perfectly in line with the seam. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [November 6, 2014, 2:34am UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/7 "2014-11-06T02:34:02Z")
Looks like the bottom half of the hole was bricked up. It probably served as drainage for the bridge until someone complained that their toddler might slip thru the hole to his death on the rocks below. Insurance company then made the city render the drainage system useless. This’ll now allow cars to skid out of control during heavy downpours, and slip over the railing to a fiery doom on the rocks below. ---
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [November 6, 2014, 2:38am UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/8 "2014-11-06T02:38:51Z")
> [@Lukeinva](#): > > Possibly at one time that bridge was a draw bridge, and the holes held some kind of draw bridge part. There is a clear separation in the bricks that are perfectly in line with the seam. It’s over a teeny tiny little stream. > [@Squink](#): > > Looks like the bottom half of the hole was bricked up. > It probably served as drainage for the bridge until someone complained that their toddler might slip thru the hole to his death on the rocks below. Insurance company then made the city render the drainage system useless. This’ll now allow cars to skid out of control during heavy downpours, and slip over the railing to a fiery doom on the rocks below. It looks like one of them was repaired, as you described, but the other side appears to be untouched original equipment. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [November 6, 2014, 2:52am UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/9 "2014-11-06T02:52:07Z")
this is an indication that it was a toll bridge. if the bridge didn’t produce enough revenue then chains and hooks were used to move it to a better location. ---
**Author:** ![I.Dunno](https://avatars.discourse-cdn.com/v4/letter/i/9f8e36/32.png) [@I.Dunno](https://boards.straightdope.com/u/I.Dunno)\ **Post date:** [November 6, 2014, 2:55am UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/10 "2014-11-06T02:55:10Z")
> [@Squink](#): > > Looks like the bottom half of the hole was bricked up. > It probably served as drainage for the bridge until someone complained that their toddler might slip thru the hole to his death on the rocks below. Insurance company then made the city render the drainage system useless. This’ll now allow cars to skid out of control during heavy downpours, and slip over the railing to a fiery doom on the rocks below. The opening on the **other** side does not appear to have been bricked up later. Also, what appear to be the letters DP are stenciled above the opening if that is a clue for anyone. I DO like your imaginative description of a possible automotive tragedy though. ---
**Author:** ![Lukeinva](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lukeinva/32/17872_2.png) [@Lukeinva](https://boards.straightdope.com/u/Lukeinva)\ **Post date:** [November 6, 2014, 2:55am UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/11 "2014-11-06T02:55:38Z")
Toll road :dubious: possibly. Maybe the holes held the pole that stretched across the bridge, at the toll plaza. ---
**Author:** ![Polar\_Iceman](https://avatars.discourse-cdn.com/v4/letter/p/f9ae1b/32.png) [@Polar\_Iceman](https://boards.straightdope.com/u/Polar_Iceman)\ **Post date:** [November 6, 2014, 4:48am UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/12 "2014-11-06T04:48:35Z")
> [@johnpost](#): > > this is an indication that it was a toll bridge. > > if the bridge didn’t produce enough revenue then chains and hooks were used to move it to a better location. Surely you meant “troll” bridge. The trolls hide in the holes, and jump out to collect tribute from travelers. Those that don’t pay, well… It could ruin their weekend. You know the old saying: “fee, fo, fi, fum. I smell the blood of an Englishman.” ---
**Author:** ![Fubaya](https://avatars.discourse-cdn.com/v4/letter/f/c2a13f/32.png) [@Fubaya](https://boards.straightdope.com/u/Fubaya)\ **Post date:** [November 6, 2014, 5:17am UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/13 "2014-11-06T05:17:50Z")
> [@johnpost](#): > > this is an indication that it was a toll bridge. > > if the bridge didn’t produce enough revenue then chains and hooks were used to move it to a better location. I think that would be a “tow” bridge. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [November 6, 2014, 7:10am UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/14 "2014-11-06T07:10:10Z")
There looks to be a small sign plate above the hole, but I can’t zoom on this device. What is it? ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [November 6, 2014, 10:57am UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/15 "2014-11-06T10:57:14Z")
> [@Mangetout](#): > > There looks to be a small sign plate above the hole, but I can’t zoom on this device. What is it? Says “DP” - could mean Drainage Point? ---
**Author:** ![Steven\_G](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/steven_g/32/5080_2.png) [@Steven\_G](https://boards.straightdope.com/u/Steven_G)\ **Post date:** [November 6, 2014, 12:27pm UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/16 "2014-11-06T12:27:21Z")
> [@bob\_2](#): > > Says “DP” - could mean Drainage Point? Don’t Peek 😃 ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [November 6, 2014, 12:41pm UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/17 "2014-11-06T12:41:54Z")
I’ve seen DPW (department of public works) on manhole covers. ---
**Author:** ![MedellinMike](https://avatars.discourse-cdn.com/v4/letter/m/c6cbf5/32.png) [@MedellinMike](https://boards.straightdope.com/u/MedellinMike)\ **Post date:** [November 6, 2014, 12:56pm UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/18 "2014-11-06T12:56:25Z")
That is odd. It may have something to do with the drainage as others have said. Though I’m not sure how that would work. I did find this: [http://freepages.genealogy.rootsweb.ancestry.com/~batsto/Towns/Crosswicks/Bridge.html](http://freepages.genealogy.rootsweb.ancestry.com/~batsto/Towns/Crosswicks/Bridge.html) showing that this location had been the site of a historical covered bridge. Perhaps it has something to do with that. Many times for historical or preservation reasons certain architectural details are added to new structures to mimic older ones that are being replaced. One other possibility. This was some kind of blockout or pass through for a utility of some sort. This seems unlikely though ---
**Author:** ![Space\_Vegetable](https://avatars.discourse-cdn.com/v4/letter/s/6de8d8/32.png) [@Space\_Vegetable](https://boards.straightdope.com/u/Space_Vegetable)\ **Post date:** [November 6, 2014, 1:03pm UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/19 "2014-11-06T13:03:03Z")
The bridge has a few similar holes, but it looks like the others aren’t open; there’s something in them. One looks a bit like a curved metal reflector. My guess is they once held lights. ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [November 6, 2014, 1:40pm UTC](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828/20 "2014-11-06T13:40:59Z")
> [@bob\_2](#): > > Says “DP” - could mean Drainage Point? Obviously, the bridge has been Dual Penetrated, and they were proud enough of the fact to label it so. [Next page](https://boards.straightdope.com/t/why-does-this-bridge-have-two-holes-in-its-brick-walls/703828.md?page=2)