# Arbor pit?



## derekleffew (May 19, 2010)

A number of college theatres built in the 1960s/70s in Ohio (and I assume other places) with rigging by Tiffin Scenic Studios, have a single purchase counterweight fly system where the floor blocks are not at stage level, but one story below.

Can someone explain the purpose of this, and is it common in other places?


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## NJLX (May 19, 2010)

I don't know why it's like this, but we have the same thing in one of our newer spaces(built in 2004), in Boston.


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## GreyWyvern (May 19, 2010)

A quick google search of "arbor pit" brought up this. The following is from a little more than halfway down the page. It is interesting and seems to make some sense. I hadn't heard of this before.


> The Arbor Pit
> 
> The arbor pit is a fundamental part of the rigging system, and is built to save money. When running any rigging set up and down, the arbor, not the pipe batten, hits its up and down limits of travel first. The arbor can be 9' long or longer. This loses roughly 9' of travel. Therefore the batten high trim is limited by the arbor length far below the grid. The pipe can't travel higher because the arbor has already hit the floor. This wastes the expense of building a high grid and high stage house. It is possible to regain the use of the otherwise wasted space between the high trim and the grid in several ways. We find the best way is to use an arbor pit. This pit gets the stage floor out of the way under the arbors and so extends the arbor travel downward below the stage level so the high trim can be extended up to the grid.
> 
> This all sounds like hocus pocus until one takes the time to lay out the rigging both ways and compare the differences. An arbor pit has the same effect on the high trim as raising the stage house roof, and it's a lot cheaper. Arbor pits are not recent inventions, but still many people haven't heard of them, possibly because arbor pits are tucked out of the way and sort of invisible. Even though they are not often noticed arbor pits are mainstream stage technology today. Most new theaters have single purchase rigging and have an arbor pit.



The whole article seems to have lots of good info from the quick look I took at it.


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## philhaney (May 19, 2010)

derekleffew said:


> A number of college theatres built in the 1960s/70s in Ohio (and I assume other places) with rigging by Tiffin Scenic Studios, have a single purchase counterweight fly system where the floor blocks are not at stage level, but one story below.
> 
> Can someone explain the purpose of this, and is it common in other places?




GreyWyvern said:


> Therefore the batten high trim is limited by the arbor length far below the grid. The pipe can't travel higher because the arbor has already hit the floor.



I was going to suggest this reason, only I was going to go the other way. At the venue where I work we don't have an arbor pit. Our pipes fly all the way out to the grid, but because of the height of the arbor and the tension block, we can only fly them in to roughly 7 or 8 feet above the deck.


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## michaelburgoyne (May 19, 2010)

As theatre consultants we often have to explain the benefits of arbor pits to architects and our clients. We routinely include them in new facilities with single-purchase counterweight systems, they are are most useful in "short" stagehouses without a gridiron. If you have an 80'-0" flytower with a grid, the roughly 8'-0" height that the grid occupies at the top of the tower will help to offset the height of the arbors when calculating your batten travel. If the facility has an orchestra pit the stagehouse footings will be at least 8'-0" below stage level anyway, so the arbor pit is relatively inexpensive to construct. Adding an arbor pit to an existing stage is, of course, much more complicated.


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## JBrennan (May 20, 2010)

We have an arbor pit in our space as well, built in '96, for all the reasons mentioned above. Also makes it easy to adjust the tension blocks if the need arises, and around here at least a precious few extra square feet of space to store rigging hardware, extra blocks, etc.


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## HornsOverIthaca (May 20, 2010)

I've heard it also called "the arbor well" from the riggers I worked with. Therefor gridding a pipe is sometimes called "taking it to the well." I've only heard one person say that but it sounded nice.


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## themuzicman (May 21, 2010)

There is a new theatre breaking ground by where I live, and on the plans they have a single story arbor pit to be constructed, for all the above reasons. It's nothing limited to older houses!


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## epimetheus (May 21, 2010)

Rudder Auditorium at Texas A&M College Station has what you could call an arbor pit. The main diffference is the pit floor is really just the basement floor as there is a basement under the entire stage. I'd say the floor blocks are about 16' below the stage deck. The floor blocks are in an isolated room in the basement.


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## metti (May 24, 2010)

When I was in middle school, their theatre which is in Boston and was constructed in the mid '90s had an arbor pit. I think that it was done that way to minimize the space that is eaten up by the fly tower in a building with other arts facilities on the second floor.


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## Sony (May 25, 2010)

This feature is still being installed in brand new theatres, mostly in ones with no grid. The new Newton North High School which is scheduled to be completed on the 1st of this June has an Arbor Pit since we have no gridiron. Like already stated, since we have a limited grid height of 48' and a proscenium opening of 20' with 7' Arbors. If we didn't have the Arbor pit we would only be able to fly say a 22ft tall drop to be even with the top of the proscenium opening since the pipe would only fly out to 42ft. The 5ft Arbor pit lets us fly out to the full 48' and still be able to come all the way in to 4ft off the floor for loading. This helps hide larger drops if needed and makes loading easier since it doesn't require a ladder or reaching over your head.


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## josh88 (May 27, 2010)

hooray Tiffin scenic being about 45 minutes from home. The title caught my attention and then reading it I went hey, this directly relates to where I'm living hehe.


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## ruinexplorer (May 27, 2010)

Sony said:


> The new Newton North High School which is scheduled to be completed on the 1st of this June has an Arbor Pit since we have no *gridiron*. Like already stated, since we have a limited *grid *height of 48' and a proscenium opening of 20' with 7' Arbors.



I'm confused. Do you mean that you have no (or very limited) fly gallery?


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## Sony (May 27, 2010)

ruinexplorer said:


> I'm confused. Do you mean that you have no (or very limited) fly gallery?



Yea...sorry the word escaped me at 2am when I posted that...

We have no fly gallery, all the blocks are underhung from the I-Beams in the ceiling and can only be accessed by a boomlift. Even the Genie AWP-40S cannot reach them they are too high up, about 4 feet out of reach.


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## SteveB (May 28, 2010)

The 2 big advantages:

- Saves on building height. As mentioned by others, you can cut 8 or so feet off the roof to account for arbor travel. You now build the travel into the basement, which ofteh times exists as part of the building design. 

- Allows the pipe to grid, which can be VERY useful, also allows the pipe to come to floor level (if the rigging system is correctly designed). It cannot be overstated how useful it can be to attach scenery direct to a batten that is at or near deck level. Means no arbor travel while weighted with no countering scenic load.

- One mjor issues can be the fire rating of the arbor pit, which becomes part of the stage area and needs isolation for fire rating, from other adjacent area's of the basement. 

- Also needs a building with a basement.

Steve B.


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## DeanH (Jul 20, 2011)

Hello,

I'm replying to this thread, because I'm looking for pictures of an existing Arbor Well (Pit). I'm working on a class in counterweight rigging for some of our less experienced employees. I noticed some of you worked in venues with a pit, could someone please send me a good picture of an Arbor pit?

Thanks,
Dean H.
[email protected]


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## Grog12 (Jul 20, 2011)

DeanH said:


> Hello,
> 
> I'm replying to this thread, because I'm looking for pictures of an existing Arbor Well (Pit). I'm working on a class in counterweight rigging for some of our less experienced employees. I noticed some of you worked in venues with a pit, could someone please send me a good picture of an Arbor pit?
> 
> ...


 
Send a PM to user ack the theatre he works at just put one in and he may be able to help you.


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