The following is a post by Guest Blogger, Dave Bauer. He is also the author of the article Stealth Benefits of Smoke Guard.
How many times have you said this: “Smoke Guard’s M200 comes in two sizes.”?
Well, if you’re like me you’ve said it a million times. If so then also like me you’ve been wrong a million times,… or at a minimum you’ve oversimplified things. Here’s the scoop. It is true that the M200 comes in two sizes in the most basic of terms; we say it’s available for 3’-6” and 4’-0” elevator doors. Elevator manufacturers have traditionally used 2” jambs, and if that dimension is added to that 42” (3’-6”) elevator door, that applicable M200 would have a clear dimension of 46” from the inside of one auxiliary rail to the other. Alternatively, that clear inside dimension of the larger M200 is 52”, or 4’-4”.
Okay… why are you complicating something that is so simple?
Here’s why. Granted, you can order an M200 compatible with only two different doors sizes (on paper), but there are options to accommodate different jamb sizes.
Otis Elevator manufactures units with 2 7/8” jambs, so in response Smoke Guard manufactures an option for the M200s for those larger Otis jambs, which naturally increases the inside dimension between our rails. Similarly Schindler manufactures units with 4” jambs, so in response Smoke Guard manufactures an option for the M200s for those even larger Schindler jambs, further increasing the inside dimensions between our rails. So in reality we have a total of six different inside clear dimensions as follows:
M200 for a 3’-6” Elevator Door
46 ¼” clear inside dimension w/ standard 2” jambs
48” clear inside dimension w/ Otis 2 7/8” jambs
50 ¼” clear inside dimension w/ Schindler 4” jambs
M200 for a 4’-0” Elevator Door
52 ¼” clear inside dimension w/ standard 2” jambs
54” clear inside dimension w/ Otis 2 7/8” jambs
56 ¼” clear inside dimension w/ Schindler 4” jambs
So big deal, how does this change my life?
Consider a project in which we at first think we cannot use an M200, but one in which the price of the M200 keeps us in the game. You can call the elevator anything you want, but at the end of the day it’s the dimension that counts. As an example, below are the standard drawings for a Thyssen Krupp SN003 Synergy Traction Elevator. The door is shown as 3’-0” so in the most elemental sense we might say that we cannot use an M200. But think outside the box. If this elevator has 2” jambs added to the 36” door, the clear outside dimension is 40”. You literally could use any one of the six size options for this elevator.
Check out the M200 example shown below. Without knowing anything about this project, the inside dimension between the M200 auxiliary rails is greater than the dimension to the outside of the elevator jambs. If the example below was a photograph of the project for which the drawing above was applicable, we could then be using an M200 for a 3’-6” elevator with standard 2” jambs (total inside dimension of 46”).
Now there clearly is a residual gap between the interior of our rails and the exterior of the jambs, but so long as that is clearly communicated to the architect they may still opt to use that for a variety of reasons. What it accomplishes is an alternative at a much lower price point.
What we take away from this is that the M200 is applicable in more situations than we give it credit for and is a great tool.