shrug-l: Numbering Hydrants

Rick Labs rick at
Sat May 7 13:57:07 EDT 2016

Scott's hydrant numbering challenge is fascinating. Considered quite a 
few options and rejected them but found one with some initial appeal:
*(For all lat/lon labels I assumed 1 meter accuracy so 6 decimals on the 
lat and long*)

Useless without reader. How to securely attach? Weatherproofing? 
Overkill for fixed locations? If cable attached the iron hydrant may 
block the RF?
**QR bar code*
Could encode a very precise lat lon. However the bar code might need to 
be fairly large? Fairly high resolution? Not readable by a human without 
a QR equipped cell phone and none of the handset makers ship them with 
QR recognition as a standard feature. Perhaps not a multi decade 
technology winner? Could also print the URL on the label but that would 
be large.

*Unique key number, plus perhaps a check digit*
x - perhaps a check digit

However I wanted "the system" to work for any County. So estimated the 
max at population of County / 3 people per hydrant for a generous upper 
end estimate. Used Los Angles County as worse case, so need a million 
hydrant capability. Perhaps overkill.

Then thought, this isn't good at all*at County / State boundaries* 
(potential confusion if the neighbors also have a "home brew" hydrant 
number system)

So...embed State and County:

x - check digit
12- FIPS state code
345 - FIPS county code
000-000  - a unique hydrant key number

This might work, but would it be subject to drifting boundaries over 
multi decade periods? Plus its long.

*lat/lon with 6 decimals*
That's a lot for a label, plus its a lot to write down / communicate 
over the phone. Reasonable font size? Curvature of hydrant?

*lat/lon and somehow reduce the digits by assuming it's all in one county
*You mark the hydrant /xyz County/ then reduce some digits on the lat 
and lon that are fixed across the county and assumed. Looked at San 
Bernadino County and basically you need all the digits in lat and lon so 
no significant reduction. So, that was a dead end.

*Do nothing
*no hydrant markings (continue to use prior system)

No coding on hydrant but create a high accuracy ground survey (lat/lon) 
and make the points .shp file public. Perhaps shoot for Land Survey 
Marker accuracy.  (Horizontal and Vertical Control Benchmark level 
accuracy). This could be very handy to have as hydrants are much easier 
to find vs. embedded markers. Standard disclaimer -/not to be used for 
survey work./ (....but to the center tip of the hydrant would in fact be 
quite accurate).

Then use applications such as Open Street Map to create maps in real time.

Maintenance would need to use the full lat/lon "ID" on service paperwork 
(long but not impossible if truncated to 6 decimals) Most service people 
would have or would be moving to cell phones for data entry, so they 
could see a map and just select the correct hydrant (avoiding the need 
to key in the lat/lon digits)

*lat/long and encode the digits _using also letters_
Using letters and numbers I think the lat/lon (at 6 decimals of 
accuracy) can be expressed in just 8 characters!

example 12BY-F89U
Easy to label the hydrant, easy to read and communicate

Here's how I envisioned it:

26 letters to start, but need only 22
ELIMINATE  "O" (number 0), "L" (number 1), "Z" (number 2)
ELIMINATE "Y" (don't need)
01234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ (a total of 32 possibilities)
number above 0-31;  in binary 00000 to 11111 (5 bits per character)

Convert lat long to binary as follows, use position to imply decimal.
sign of lat    1 bit
lat integer (3)    8 bits (use 3 digits for consistency, yes it could 
fit in 7 bits but not much savings)
lat decimal (6)    10 bits
sign of lon    1 bits
lon integer (3)    8 bits
lon decimal (6)    10 bits
spares    2 bits
Total    40 bits

characters hold    5 bits
characters needed    8

The conversion alog is simple and quick, can be expressed in Excel, run 
on a cell phone, executed in any Javascript in a browser.

Just one caution (easily checked and avoided during assignment) - 
letters sometimes form words some words might best be avoided (very rare 
but possible)

Come to think of it, that coding would be a nice replacement to Zip 
code. One meter accuracy could "hit the mail box")

*Optional add on*
If you are going to the expense of marking each hydrant perhaps add a 
bit more info:

Report any issues
If emergency call 911 with above 8 character code.

Website instantly returns nearest cross street, standard precision (6 
decimals) and high precision coordinates (lat/long/altitude) of that 
particular hydrant. Presents interactive web form for further needs. 
Something like:


        Medical / Ambulance / EMT

    Mechanical issues:

        Potentially life threatening
        Active leak - major
        Broken / not functional / missing parts

               Active leak - minor (up to a 1-2 gallons per 24 hour day

        Needs paint


Also thought hydrant codes that were really lat/lon could be very 
helpful at coordinating "massive" emergent services, such as 
food/medicine drops after an emergency that blocks roads. Having a 
national/international system would be ideal.


On 5/3/2016 5:10 PM, Scott Warner wrote:
> Does anyone have any ideas or ways that they have numbered their fire 
> hydrants countywide that would make sense to the fire fighters that 
> inspect and use them as well as make sense to a person that looks at 
> it on a map? We’ve talked about doing a grid but nothing seems to make 
> sense when brainstorming this idea.
> We want to leave room for growth but yet consider cities and hope they 
> buy in to a countywide numbering system.
> Thank you,
> *Scott Warner, GISP, FPEM*
> Public Safety GIS/ 9-1-1 Specialist/WebEOC Administrator/
> Special Needs Registry Technical Specialist
> Bay County, Florida Emergency Services
> 700 Highway 2300
> Panama City, FL 32409-5090
> Main:    (850) 248-6040
> Direct:  (850) 248-6041
> Fax:       (850) 248-6059
> LAT:  30.2990648    LONG:  -85.6622406
> USNG:  16RFU2864152683
> Past President- Florida Chapter of URISA
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Richard J. Labs, CFA, CPA
CL&B Capital Management, LLC
Phone: 315-637-0915
E-mail (preferred for efficiency): rick at
Mailing address: 8 Laureldale Dr., Pittsford, NY 14534-3508

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