hello everyone,

at EOOS Design we are currently working, together with Eawag on the RTTC Project ´Diversion for Safe Sanitation´. You can find some more information in this tread.

Now we want to provide the users with the best urine diverting squatting pan possible. As from what we have heard, seen and tested ourselves, it´s very easy to screw up here.
It would help us (and I think everyone else working in that field) to have a good collection of benchmark pan geometries to test prototypes against.

It would be super helpful, not only for us, if you could join in and share the plans or 3d CAD files of the squatting pan you developed or scan any good (or bad?) pan you have access to (for example with this free software: www.123dapp.com/catch )

Let’s share and together build the best urine-diverting squatting pan!

We´ll make a start and share our pan as well as a scan of a common Chinese pan:
link to the 3d geometry below the images






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Dear Bernhard,

I would like to help, but I am a bit confused about this 3D Scan thing.
Does it help you to have access to photos, can the dimensions be taken from there?
When I was at GIZ, we had compiled a list of manufacturers for urine diversion squatting pans and pedestals, so you can see a whole range there (probably you have already seen this document?). See here for the list of squatting pans:
susana.org/lang-en/library?view=ccbktype...p;type=2&id=1147

And of course there is the huge photo collection of SuSanA on flickr, see e.g. here a set on urine diversion squatting pans:
www.flickr.com/photos/gtzecosan/sets/72157626364669195/

But I guess photos don't help you and you need those scans? How can someone who has a urine diversion squatting pan in front of him/her get such a scan done?

By the way, what is your experience: my feeling is that for public toilets and schools the squatting pans are good, but for home use many people do aspire to sitting toilets (even if they are supposedly from a "squatting culture"). Sitting is often seen as the more upmarket way (even if health and hygiene issues seem to point as squatting as "superior").

Regards,
Elisabeth

I'd prefer a design with the following details:

• distance between urine bowl and faeces hole can be adjusted
• hole size for faeces can be adjusted (e.g. inlay rings)
• round edges for easier cleaning
• easy method for closing all holes in order clean the surrounding area with fluids
• some form of splash guard protection
• overall optimal hydraulic discharge where applicable (~ cleaning)
• coated surface

I like the idea of pooling an open source design for the optimal pan design. Could you provide any dimensions for the design? i.e. shape, size, etc.?

(I like the Flickr set Elisabeth linked to - most designs are still very rough, though, so the design approach makes a lot of sense, imo).

Dear Elisabeth,
Thank you for your help! Yes, I know the document. Also the SuSanA flickr account is a very valuable resource for us!

regarding 3d scanning: there are several possibilities but with 123d catch its fairly easy. And the software is free.
Basically you take a bunch of photos of an object, about 40+, from all sides. 123d catch then turns them into a three dimensional object. Works a bit like making a panorama picture...
There are a bunch of explanatory videos on their website as well: http://www.123dapp.com/howto/catch#videos

Dear Jürgen,
Thank you for your feedback and input!

I totally agree with round edges, easy method for cleaning (with fluids), splashguard respectively easy discharge.
Could you explain in a bit more detail the ideas about flexibility in feces hole and distance to urine part of the pan?
The reason why I´m asking is because up until now I was thinking: Feces hole - the bigger the better as long as ventilation still works and there is no danger for children to fall into it..
And on distance between feces hole and urine area: the feedback, especially from female users was: the smaller the better. Sure - the urine area (bowl) has to have a certain size but shouldn´t it start right in front of the feces hole to be able to catch all the last drips?

Maybe we are missing something here so I´m really looking forward to reading your thoughts on this.

According coating of the surfaces: I agree but it’s a difficult thing. We are looking into that as well but we believe that first the geometry must be the right one. The coating can only make it better, but it´s not a silver bullet.


@ sitting vs squatting: well - we also had long discussions But the feedback we got in Uganda was a clear "pro squatting" if the toilet is used by more than a very (very!) limited number of people. So we will focus on squatting for now.

concerning dimensions: sorry - you´re right.
I just added a plain 2d drawing of the thing with dimensions to the dropbox folder were you can also find the complete 3d CAD files. (link in first post)

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edit: these dimensions are our current work in progress. they are by no means to be iterpreted as a good squatting pan ..yet.
some things to improve on:
- the narrow area between the heels is to narrow (its too easy to pee on that area)
- footsteps should be placed further apart
- flush-channel needs to be closed in the middle so water can´t enter the bowl dead-center (to prevent splashing over into the feces hole)

+ positive felt the thin "line" between feces hole and urine area (but that might be up do discussion - see above)
+ positive was also that due to the flush there was far less urine odor compared to our chinese pan.

more tests, assessments and improvements to come...

This may be wonderful for squatting toilets!

Yet I wish somehow someway people could slowly be turned to seat toilets. I seen one vido where a person after sitting on a seat stool then placed his feet on a tall bench to by that means attain a bit of the squating position. Seat toilets rather than squatting holes allow more room for the waste without digging a hole or building a higher toilet structure. Only the more weathly should be able to afford sqatting toilets and they likely don't want them. Surely some old people and crippled people need seat toilets, and why cannot others use them as the fact that old and crippled people need them, prove they are easier to use.

Some of my thoughts
Blessings

Amos Bender

Amos wrote:


There are also people who think the other way round and try to convince people that squatting is better (e.g. healthier) than sitting. You can even buy stools that turn a sitting toilet in a squatting toilet, e.g. this one.

But my opinion is that we (sanitation practitionners, experts, consultants etc.) should not try to change people's preferences in this sense, but rather understand what is important to them and offer solutions that are well accepted and percieved as comfortable by the users.

So if in the case of the Eawag project, the users (in Uganda) clearly expressed the wish for squatt toilets, it is certainly the way to go. Of course the resulting toilet may not work so well in contexts where people prefer sitting toilets.

Hello SuSan Readers,

I wanted to share a quite different squat toilet design that I was thinking about and created with Google Sketchup. The unique gate remains inside the urine pan and acts as part of the urine pan and is only (slide ahead) opened for defecating. Except for defecating and all other times this gate both blocks the solid waste area as well as increases urine diversion. The pros are it obstructs odor and the unsightly, and increases urine diversion. The con is it needs opened for defecating and which some might forget. Yet the gate then could easily be tipped up with the handle and the feces dumped through the opening. Obviously if people are careless even without a gate, feces can make a mess. The open and close lever could be attached to the back side of the gate if desired. Your comments or suggestions are very welcome.

Blessings
Amos

Thanks Amos, Thanks Gerwin (and the whole TU Delft crew ; )

wow - super cool stuff. Thanks for sharing!

Gerwin, at the moment we do not use any statistic data. Only our friends and colleagues. ...and not everyone of them is used to squatting.
I wasn´t familiar with the work of Chakrabarti - did he also work specific on the toilet squatting posture?

plug and play reminds me of the ideas Jürgen had (see above post #3555) with adjustable distances and sizes

Amos, I really like the idea of the lid. Decreasing the size of the hole or closing it completely really helps with odor. Lately we did some experiments with a rotating lid but its tricky as well. Subjectively it feels more "dirt proof" to me than a sliding mechanism. I think big tolerances and contact area, like in your design, is a good approach.

Bernard,

Here's the book where our team member got the data from.
books.google.nl/books/about/Indian_anthr...MAAJ&redir_esc=y

I don't have a full copy here, but I can see if I can get it through our team member. As I understand the data relates to squatting. There is, however, no data for children in that book. That's why we collected it ourselves.
I understood EAWAG/EOOS is focusing on people in Uganda? How inclusive is your design? All ages, genders, disabilities, etc.?

Maybe it's a good idea to make a list of resources for squatting anthropometrics & ergonomics:

- Chakrabarti (1997): Indian anthropometric dimensions for ergonomic design practice
- Alexander Kira: the bathroom
- Johan Molenbroek: A Friendly restroom, developing toilets of the future for disabled and elderly people
- dined.io.tudelft.nl/dined/full (this is our database for international measurements; no squatting dimensions here, but all the other postures and body features you can find here)
- ...

I hope we can make this list a bit longer together with you guys!

Cheerio,
Gerwin

Gerwin
Thank you for the post.
The book sounds very interesting, so we wait for it

Yes at the moment we are focusing on people in Uganda, and we´re trying to make a design for all ages of course focus on adults.
Maybe there will be a kind of grab rails that helps older people or disabled, to stand up or going to squatting.

At the moment I really think about the diversion how high it has to be, that it´s good enough to control the diversion but it should still be comfortable.

Currently we try to lead to the correct position via the footsteps. The splash guard gives some guidance as well, but the footsteps are more important. What do you think?

I really like your posts, keep going!

one additional anthro resource for kids: ovrt.nist.gov/projects/anthrokids/

alexander kira - jep: a wonderfull book! sadly it´s very hard to get. We have one and plan to make a "backup copy" the next days... pm me...

I have to look into the other books & dined

Thnx

Thanks to you all for your encouragement. As I said in another post this is a wonderful forum to share our ideas and thanks to those who started and are running it. As also stated before feel free to copy any of my designs or features I have shown here or in other of my posts. Although I would be pleased to be informed if someone does want to copy something, that is not so important, while helping those who need it is.