On 9/2/07, Jim Lux <email@example.com> wrote:
> Kelly wrote:
> These types of set back limits *should* be easy to fight. How many
> ordinances can you name that allow for a 35 foot tall house to be
> erected 10 feet from the property line? How many cities allow 10
> story tall buildings to be built right next to someone else's
> property? What about skyscrapers next to public streets? What if the
> skyscraper falls? They never fall, right? Remember 9/11? Remember
> San Franciso earthquakes? If towers must be a distance from the
> property line equal to their height, then so should every other
> manmade structure. What about street light poles? What about utility
> poles? They don't have to meet these requirements. Why ham and cell
> towers? It's simple. These types of set back rules are simply
> another "back door" way of limiting tower height. They have nothing
> to do with safety.
> A couple significant differences..
> 1) People have been building houses for centuries, so there is extensive
> experience and tradition with allowing small setbacks
Towers and other structures are built ALL THE TIME which are tall
enough that they could cause significant damage to the public or to
neighboring properties should they fall. Why is that? Simple.
Someone decided that the risk was worth the reward AND they required
it to be structurally sound. Ham towers and cell towers can also be
made just as structurally sound to reduce the risk to the same level
as these other structures. So, why are ham towers and cell towers
then limited when these other structures are not? Simple, because
people want the height limited not because of safety but for
aesthetics. Is it 100% "safe" to fly commercial airliners over
residential neighborhoods on their approach to an urban/suburban
airport? Of course not. There are numerous cases of plane crashes in
residential neighborhoods which killed numerous people. Do we ban
urban/suburban airports? Of course not. Do we require a 100% safety
margin? Of course not. We make things as safe as possible and live
with the remaining small amount of risk. Why then, do ham towers have
to have a 100% safety margin?
I have absolutely no problem with requiring ham towers to be
structurally sound and to go through similar safety analysis as
commercial towers, esp. when they are close to a setback or property
line. What I DO have a problem with is the unvarying height limits
for towers which are there only to limit the number of NIMBY's that
will complain (due to aesthetics) rather than improve safety. If you
want to improve safety, then improve safety, don't just limit height.
Most height limits are there for aesthetic purposes, not safety.
Actually, I suggest that the height limits are there specifically to
limit the number of NIMBY complaints. A 35 foot tower is FAR MORE
intrusive for my next door neighbor than an 80 footer. All of the
aluminum is at 35 feet instead of 80. My neighbor would rather I have
an 80 footer than a 35 footer. The guy one block away, however, would
rather I have a 35 footer because then he can't see it. So, which
tower will draw more complaints at City Hall? The 80 footer of course
and THAT's why they like to limit height.
> 2) Houses are typically wider than they are tall, so they tend to fall
> in place because of the internal bracing. Towers are long and skinny
Agreed, but what about skyscrapers? What about Sutro tower in San
Francisco? What about the Bay Bridge? What about billboards, utility
poles, etc.? What about any number of other "structures" which are
allowed to be tall enough that if they fell over they'd land on
private property? They are essentially allowed because someone
determined that the public good was more important than a 100% safety
margin. Ham towers aren't given that level of importance.
> 3) Tall Commercial buildings *do* require failure analyses
And ham towers should be required to meet safety standards as well, if
they are close enough to setback/lot-line to potentially cause damage.
Make them safe! No problem with that.
> 4) there *are* restrictions on types of construction and design to
> prevent buildings from falling into the street in an earthquake. Heck,
> as far back as the Field Act in California (resulting from the 1933 Long
> Beach earthquake), but also more recently, all the seismic retrofit rules.
Once again, I have no problem with designing things more safely: more
steel, more windload tolerance, bigger guy lines, whatever. What I
have issue with is the height limit which limits towers to a height
which is a function of its distance from a setback or lot-line when
other similar structures (utility poles, street lights, skyscrapers,
etc.) don't have the same type of restrictions.
> towers, chimneys, etc are all regulated pretty much the same and have
> been for decades.
In most cases, towers and chimneys have height limits BUT I've never
seen one that had a limit which was a function of distance from the
setback. In San Jose, Ca. (where I used to live) your chimney could
be 35 feet height and could be 10 feet from the property line.
Nowhere in the rules did it say that your chimney height had to be <
the distance from it to the property line (like many ham tower
regulations around here do).
> What's different is that hams are no longer getting a free pass on these
> sorts of rules. And, in general, communities are being stricter in
> general, and ham towers are just getting sucked along for the ride.
How many times do I have to argue that additional safety is a good
thing. Yes, hams in alot of cities have built some pretty unsafe
structures close to neighboring homes and lot-lines. This should not
be allowed. They should be required to make them safe. Putting a PE
stamp on every page of a document doesn't seem to increase safety to
me, BUT if doing that would get my permit OK'd then I'd happily do it.
Fundamentally, my issue is this. I believe PRB-1 makes it clear that
rejecting a tower request or limiting its height strictly on aesthetic
grounds is not ok. So, cities use these types of "setback rules" in
order to limit height and they say ("it's for the children") it's for
safety reasons. I don't believe it is for safety reasons at all.
It's really for aesthetic reasons, but they can't say that so they use
"safety" which carries more weight. Sorta like hams that use "public
safety" as their justification for their towers. I must admit, both
sides are doing the same thing :-)
> Jim, W6RMK
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