MEMORANDUM
July 16, 2002
TO: Keith Porter, Tara Hutchinson, William Holmes (and Nicos Makris)
FROM: Mary Comerio and John Stallmeyer
HELLO ALL:
Below are the 4 methods for contents categorization that we outlined the other day.
Method 1 and 2 are based on the conversation between TH, KP, MC, and JS. These
represent an “engineering description” of possible building contents. Most notable is that
there is not a hierarchy among the categories, but any combination of the factors gives
one of the 36 categories in Method 1, or any of the 18 categories in Method 2.
Methods 3 and 4 are very different. Method 3 is the one John created, and it requires a
hierarchy of choice (e.g. if you pick floor, there are different weight choices than shelf).
Method 4 is “horizontal” in that it pre-combines weights, center of gravity, and other
engineering criteria into lists of contents in groups that will perform similarly.
Building Contents Categorization Methods
Method 1 (The Long Way) 36 categories
1 Weight
0 – 20
>20<200
2 Aspect Ratio
<2/3
>2/3
3 Restraint
Good (we think it works)
4 Coefficient of Friction
>200
None (unrestrained) Some (restrained but we don’t think it is good)
Low (.4)
High (>.4)
Method 2 (The Medium Way) 18 categories
1 Location
2 Restraint
Good (we think it works)
3 Aspect Ratio
Floor
Bench Top
None (unrestrained)
<2/3
>2/3
Shelf
Some (restrained but we don’t think it is good)
Notes:
The first of these gives us 36 categories the second 18. Obviously some of these will never be
used. Aspect ratio will be estimated from photos. Coefficient of Friction is also a bit of guess at
this point as we have little to no data on what the base of most items looks like.
Here is the table Keith made to explain these categories:
Short list (18 members)
Long list (36 members)
Comment
Restraint  {none, partial, full}
Restraint  {none, partial, full}
Location  {floor, bench,
shelf}
Weight  {0-20, 20-400, > 400};
breakpoints subject to change
Location strongly correlated
with weight; may be
interchangeable.
Aspect ratio  {≤ 0.67, >0.67}
Aspect ratio  {≤0.67, >0.67}
Breakpoint per code. Nicos
have better idea?
Coefficient of static friction 
{≤0.40, >0.40}
Tara will send John tables.
Method 3 (The Short Way) 12 categories
1 Location
Floor
Bench Top
Shelf
1 Weight
<400 >400
>50 <50
<20 >20
3 Center of Gravity
(John’s educated guess – high or low)
Notes:
This method gives 12 categories. Each of the weight categories is available only to the location
category above it. This eliminates several categories that are not realistic like >200 shelf items.
Also this category includes center of gravity instead of Aspect Ratio.
Method 4 (The Bill Holmes Way) 9 categories
1.
Equipment on Floor that overturns
2.
Equipment on floor that slides
3.
Free standing cabinets
4.
Heavy and tall on wheels (i.e. electronics rack)
5.
Dewar on wheels
6.
Other wheeled (i.e. animal racks)
7.
Tanks
8.
Bench Top equipment
9.
Shelf/Cabinet (attached to wall)
Notes:
While this looks very different from the above methods it really is close to them but just
translates the general rules above into items that we have actually seen in labs.
Questions to Bill about this method:
What about other shelf types/categories?
What about latches v. no latches?
TO ALL
Before we try these on to the Cande lab (e.g. We go through and assign the equipment in the
Cande lab to the categories as a test) we thought that we should make sure everyone agreed that
these where OK and had some meaning. We are open to any suggestions, comments or
alterations to any of them.