Question about Rainbow Falls - NWRR

[TFN5459]

I haven't been able to find any photos of the "ground level" of Rainbow Caverns, but does anyone know if the individual "streams" of each color flowed together at the bottom to a common pool with the falls or did they stay as their own individual water feature? I recall reading somewhere that the colors were individualized and never mixed but I'm having a hard time visualizing that as the only photos and video that have surfaced are all in black and white and focus on the water features and not where they flow into.

[jazzfan4]

The streams had to stay separate. When first put in the colors would splash and mix at the bottom of the falls making the colors all brownish in a short time. The story I heard was that Walt told one of the Imagineers that "It's kind of fun to do the impossible" when he was trying to solve the problem.

[IDMT129]

would love to see photos or video of the original falls.

[TFN5459]

would love to see photos or video of the original falls.

As would I, the other falls like Staircase falls have appeared at least in a photo or video but Rainbow Falls seems to somehow eluded being documented completely.

[TFN5459]

The streams had to stay separate. When first put in the colors would splash and mix at the bottom of the falls making the colors all brownish in a short time. The story I heard was that Walt told one of the Imagineers that "It's kind of fun to do the impossible" when he was trying to solve the problem.

Oh okay, thanks. I figured it was something along those lines, but without any photos it was somewhat hard for me to visualize. In all the photos and video that I've been able to find, it seemed like some of the falls shared common collection pools at the bottom but probably because they were of the same color. That Imagineer I believe was Claude Coats, whom had been told previously by a mathematician that the falls couldn't be done, to which he was informed by Walt that "it's kind of fun to do the impossible".

[jazzfan4]

I believe the "impossible solution" was fiber glass angel hair that the water flowed down into the pools with no splashing.

[Keeline]

The fluorescent effect of the Rainbow Caverns waterfalls and fountains was achieved by projecting longwave ultraviolet light (UV-A) on the water that contained six different dyes supplied by UltraViolet Products, Inc.

As the story goes, some "experts" told Walt that it would be "impossible" to keep the colors separate and in a short time the whole thing would be some gray color instead of the six bright colors desired. With some clever planning by Claude Coates, plans were made for keeping the drain channels separate and splashing minimized to prevent mixing. Although this design was not used precisely, it does illustrate the basic idea.



This is another test illustration to show how colors could remain separate:



In 1956 Rainbow Caverns started with a small number of waterfalls. This was expanded a bit in 1960.

Photographing fluorescence from UV-A is very challenging. The UV-A tends to overexpose both film and CCD sensors in digital cameras. When dealing with film, whether still or motion picture, you don't get to se the result until the film is processed. Those who collect fluorescent minerals and try to photograph them run into the problems. In the film days, the usual procedure was the use a straw yellow gel filter (e.g. Wratten 2B) to block the UV light and expose the film to the visible portion of the spectrum. Today it is possible to make some color adjustments in the camera or in post processing with Photoshop or similar tools.

I am sure that Disney wanted to film the Rainbow Caverns in all of their glory (e.g. in Disneyland, U.S.A. (1956)). However, the technical challenges were pretty great. One of the black-and-white TV shows included a very brief clip of the Rainbow Caverns that was not so badly overexposed as many likely were.

https://www.youtube.com/embed/6WB1JGFao3I

Likely most here have seen this as well as this photo from the August 1963 issue of National Geographic Magazine. It was a long and carefully-staged shoot to get these results. The "camera flash" and headlamp were added in post processing.



This ViewMaster image is somewhat less common and gives a hint about some of the intense colors. They are even more so for the eye than the film reaction in the case of fluorescence. On the left of the image is a flat painting that gave the illusion of the cavern continuing for some distance in that direction on the west side of the Caverns building. It was painted with paints that fluoresced under UV-A, much like the paints used in the Fantasyland dark rides of the era.



Here is a view that is probably not so well known but does show the color of some of the water:



One of the side effects of UV-A illumination is that the depth perception of the eyes is limited because of the relative darkness. Thus, it was not necessary to have fully three-dimensional stalactites. This photo with the lights on shows the plywood flats (much like the Fantasyland dark rides), fans, and other details:



The track leading into the Rainbow Caverns show building had curves to block the outside light and keep it as dark as possible inside. Here is the layout with the principal waterfalls of the time:



Each of the waterfalls had their own 3-view engineering drawing which illustrated the water flow. The low light and limited depth perception allowed for certain tricks. For example, the Witch's Cauldron used red and yellow water. This diagram gives a good idea of how the colors were kept separate:



I trust that this will give some insights into how this magic was performed in the Rainbow Caverns at Disneyland.

James D. Keeline
Poway-Midland Railroad volunteer steam locomotive engineer for 16 years
Mine Train enthusiast for even longer

[IDMT129]

Still does not completely show how the water collected in a common pool. Unless the falling water entering the pool was also a depth perception illusion also. The falling water most likely fell into a collection ditch behind the main body of water which was normal water without the dye.]

But it still does not answer the geyser effect.

[Keeline]

For most of the waterfalls the colored water dropped into a small pool which was recycled for that same fountain.

The waterfall with the most colors in use was "Rainbow Falls" and it used six fluorescent colors to achieve the effect. In the lower section there were small walls to prevent splashing and mixing of the colors. I added color to one of the blueprint diagrams to help illustrate. All of the diagrams have a "front" (as seen from the train), top, and side (profile) view to aid with construction of the features. Notice the pipes in the side view which show the places where water is pumped from the reservoirs.



Some falls used two colors such as Silver Threads Among the Gold (blue and yellow) and the Witch's Cauldron (red and yellow).

Most used a single color of water. Waterfalls like the Seven Sisters, Staircase, and Bridal Veil used "blue" water. Red Devil falls used just red.

Given how much blue was used, the water "river" seen in the video is probably water of that color in the first section. On the side with Red Devil and Rainbow Falls, one of the rivers could be red. The diagram for the Witch's Cauldron shows a yellow river.

The fountain showed in the photos is green and I have not seen a name or blueprints for it. However, this would contrast with any rivers for blue, yellow, or red water.

In order to be seen in the pitch-dark Rainbow Caverns, the water would need to have the fluorescent dye and be illuminated with UV-A. I don't know how much the depth of the water was a factor in its fluorescence and visibility to guests. I'm sure they experimented with this to maximize the effect.

James D. Keeline

[IDMT129]

Thanks, James. This actually helped a lot. I was 8 when the attraction closed and my memory of it is hazy at best. We used to round robin the ride late at night until the park closed. I sometimes forget how short the actual cave sequence is compared to Knott's Calico Mine Trains and Santa Cruz Beach Boardwalk time train.

I see now the red flowed only in a red pool which most likely fed the red devil's falls. I am pretty sure each color from rainbow falls fed another pool which ended in a geyser or other single color waterfall. I see now, too, the geysers were separate self-contained pools as well. I found a color video of the ride which shows a few of the falls and geysers in full techno color.

https://www.youtube.com/watch?v=QoqhzzuIhI8