Film-Tech Forum ARCHIVE: Drive-In Theatre

This is topic Drive-In Theatre - Parking Ramp Height? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=004405

Posted by Barry Floyd (Member # 385) on 01-07-2003, 11:19 PM:

Is there a "standard height" for parking ramps at a drive-in.

Like the image shown below (from cinemaequipmentsales.com), we have our site plan for the Stardust deisgned with the "double ramp system"

However, we can't find any information that clearly shows a "typical" ramp height.

We've found on the net a diagram that must have been drawn many many years ago that shows a typical ramp profile - here's the link to Brad Light's Driveinworkshop (used to be Tim Reed's site)which shows the same detail.

Drive-In Theatre Parking Ramp Detail

You can see in the "Vertical Curve Detail" in the graphic, it gives vertical elevation dimensions of 0, 3/4, 2 3/4, 6 1/4, 11, 17 1/4 spaced at 2'-0" intervals over a 10'-0" distance.

My question is..... are these vertical dimensions given in INCHES, or some arbitrary number not described anywhere else?

Posted by Adam Martin (Member # 641) on 01-07-2003, 11:43 PM:

Ramp height will vary depending on how far back in the field it is. The farther back, the less height is needed to aim the windshield at the screen.

Posted by John Pytlak (Member # 331) on 01-08-2003, 08:20 AM:

And the preferred ramp slope depends upon the elevation of the screen's horizontal centerline.

Posted by Barry Floyd (Member # 385) on 01-08-2003, 08:41 AM:

Our site will be double ramped, like shown in the bottom of the graphic above.

Our screen is 25' x 60' - with the bottom of the screen 16 feet off the ground.

The top of the first ramp is 75 feet from the face of the screen, and the top of the furthest ramp is 309 feet away from the screen.

Posted by John Pytlak (Member # 331) on 01-08-2003, 08:47 AM:

As Adam Martin said: "Aim the windshield at the screen". The ramps should be sloped so the driver and passengers have a clear "line of sight" with the horizontal centerline of the screen. Getting it right is most critical for the rows closer to the screen, and for the rear seat passengers.

Posted by Adam Martin (Member # 641) on 01-08-2003, 10:16 AM:

I bet Evans could give us a formula or two to find the ramp height based on height of screen center and distance from screen. It's all a triangle geometry thing, but I suck at math. Maybe I'll give it a shot later today after I've had some caffeine.

Posted by John Pytlak (Member # 331) on 01-08-2003, 11:48 AM:

Assuming you have a perfectly flat field, and the screen base is at the same elevation as the cars, you have a relatively simple geometry problem to calculate the angle the car should be tilted by the ramp.

If we assume a height to the center of the windshield to be about 5 feet, for your screen the vertical side of a right triangle is 16 + 25/2 - 5 = 23.5 feet. The horizontal side of the right triangle is the distance from the screen to the ramp, ranging from 75 to 309 feet. Now calculate the angle the hypotenuse (sight line) makes with the bottom side of the triangle, and have the ramp tilt the car upward by that angle.

Posted by Timothy Eiler (Member # 383) on 01-10-2003, 07:40 PM:

While getting the ramp height is important. You will still have lots of stupid people who will not park on the ramps but in between them. [Roll Eyes]

with there cars facing down and will have to be told how to park. The Way I explain it "Pretend there is a speaker on the post way up there with a 3 foot cord on it that you will need to hang in you window to hear the movie" That usually gets them to a better place. NO NO don"t run over the post you park beside it [Mad]

Tim
Starlite Drive-In

Posted by Tim Reed (Member # 137) on 01-11-2003, 12:03 AM:

An often-overlooked fact is the original purpose of the ramps is so people in the back seat of a car can see the screen. The driver is supposed to slightly adjust the car's position on the ramp until the screen comes into view for the rear seat passengers. You almost don't need ramps for front-seat occupants (almost). The overall slope of the field aids in viewers being able to see over the tops of cars in front.