Use and Care Manual

FIBERGLASS LADDER TECHNICAL MANUAL
9
An independent laboratory ran four series of temperature-load tests on single section
fiberglass extension ladders to study the effect of temperature. ANSI A14.5 Horizontal
Bending Test procedures were used with a 10 foot span and 250 lb. test load. In all but the
Series IV tests, the 250 lb. test load was removed after each deflection reading was taken
and then reapplied to the ladder when the listed temperature was attained. For the Series IV
testing, the 250 lb. test load was maintained on the ladder for the entire 4 hour time period
at the 125°F temperature listed. The load was then removed and reapplied for the 77°F
reading. Separate ladders were involved in each test. Each ladder was preloaded to
180 - 185 lbs. in a horizontal position and then unloaded prior to starting each series of
tests.
% of Room Temperature
Series Temperature Deflection Deflection
I 80°F 1.141" ---
-65°F 0.820" 72%
75°F 1.020" 89%
165°F 1.550" 136%
80°F 1.161" 102%
% of Room Temperature
Series Temperature Deflection Deflection
II 80°F 1.050" ---
110°F 1.150" 110%
140°F 1.255" 120%
80°F 1.070" 102%
% of Room Temperature
Series Temperature Deflection Deflection
III 80°F 1.075" ---
165°F 1.355" 126%
168°F † 1.380" 128%
125°F 1.050" 98%
80°F 1.045" 97%
This test is intended to simulate the condition of a ladder stored inside a van in the desert.
% of Room Temperature
Series Duration Temperature Deflection Deflection
IV 0 75°F 1.095" ---
0 125°F 1.214" 111%
1 hr. 125°F 1.298" 119%
2 hrs. 125°F 1.310" 120%
3 hrs. 125°F 1.318" 120%
4 hrs. 125°F 1.322" 121%
77°F 1.111" 101%
This test is intended to simulate a situation where a craftsman works on the
ladder in the Southern U.S.A. heat.
TEST CONCLUSIONS
1. Low temperatures reduce deflection.
2. Elevated temperatures increase deflection.
3. Ladders will recover to about their initial deflection under load after being
exposed to thermal cycling between -65°F and 165°F.
4. Deflection increases small amounts (the creep effect) when load is maintained at
elevated temperature.
Izod Impact
Temperature
(Foot-Lbs./Inch Notch) % Increase
Room 47.6 ---
-65°F 82.0 172%
FIBERGLASS LADDER TECHNICAL MANUAL
9
ENVIRONMENTAL TEMPERATURE
LOAD TESTING
† The ladder was maintained @168°F for 16 hours & then retested.
EFFECT OF MAXIMUM EXTREME TEMPERATURES ON DEFLECTION
EFFECT OF BELL SYSTEM TEMPERATURE LIMITS ON DEFLECTION
EFFECT OF EXTENDED TIME AT VARYING ELEVATED TEMPERATURES
EFFECT OF EXTENDED TIME AT A CONSTANT ELEVATED TEMPERATURE
EFFECT OF TEMPERATURE ON IMPACT STRENGTH