The Bolivar bulletin. [volume] (Bolivar, Hardeman County, Tenn.) 1865-1888, 1871-12-22
Why steam Boilers ExnIaae.

yest6 rdSy, TO witness the cOntiuuatics
lOf the experiments begun by the Uni
ted Railroad Companies Of New Jer
sey, at the suggestion and under Ia,
Immediate direction of +. b. Stsvea,
OF Eiob0ke1, 10 determine the cause q
steam boiler explotiOns. Among tn,
New York engineers present ysF,
Gen. Belknap, Chief OF the l.. 4
Board of Supervising Inspectors o
steam bOats; Erastus W. Smith; Nor,
man Wizard, Professor ThurStOn Of the
Stevens Institute Of Technology, and
Charles Hasweli. a committee Of the
Franklin Institute, OF Philadelphia
headed by Coleman Sellers, Mr.. Colin,
Mechenical Engineer of the Pennsyl-
vania Railroad, from Altoona, and
others, to the number of 80 or more,
were present.
The first experiments of this series
/ were made at Hoboken on the End of
September last hy bursting four large
boilers by hydrostatie pressure, and
+ il is the intention Of Mr. Stevens now
TO continue them daily until the sub
/ ject is exhausted. a large incIoSHre
ON the Government reservation at
! Sandy Hook including about al acre
of ground has been erected by permis-
sion Of the Secretary of War, and
! within it eight boilers have been set up
! with all the necessary appliances at
/ teched, four OF them being of the lar
I gs5t classes of mariae boilers. After
/ all present hSti observed the details OF
I the preparations and examined the re-
cord OF the previous experiments, the
fire was increased in b 1iier No. ,, built
1853, and taken ut of the CO8t in Jelly
last, after being in use thirteen years.
| This boiler was indenlicRl in shape
and general construction with the
boiler wbick exploded on the West
/ field, although somewhat smaller,
the shell beng g. feet in diameter
and y feet in length. 1t was testPSi
| TO 81 pounds water pressure without
! fracture on the previous occasion, and
later had been subjected to 90 pounds
steam pressure. Yesterday the steam
! press IRE was raised gradually tO 93
pounds. The boiler began to leak
steam slightly at n I.ressure OF -
pounds, and the leaking increased as
tiia press ire rose, till at the highest
point attained the pressure began to
Tecesle, the leaks having increased in
the extent until the steam escaped ~
fast as generated. After waiting half
an hour for Tire fire 10 burn out parti-
ally, the doors were opened and the
fires banked. At TIE end of the Sec
N'aitA nan AAOhi IaAC III ~ Ct0 " lttA-
drawn altogether, the steam pressure
having gone dow to ~ pounds. Soon
after the fires were drawn an extan-
siye leak started ia one Of the fur
nGCeS, probably from the sudden csSOl-
ing and contraction, and upon exam
inatiOn the h0iler was found To b.
much distorted. The wagon top had
sunk down about two inches, aud =
corresponding swell was observed in
each side, just below the depression.
All the longitudinal seams Of the
shell were also leaking, while no
leaks were to be seen along the trans
verse seams. The experts present
seem to think it remarkable That an
old rotton boiler ofsuch large dimen-
sions should be able to withstand such
an extraordinary force Of steam, and
of cO'irse no satisfactory explanation
could he drawn from this experiment,
ss 80 why other boilers of like demen-
/ tioiir, and seemingly much greater
strength, should explode, even while
new, not only with p lower pressure
of steam than this one withstoOd, but
also with q pressure much lower than
thst 10 which they had been subjected
duriDg tue water test.
The second experiment was upon
IN. q. boiler made with two fiat
SKI lsl-ES lfIDs sG~EAfNlltZ TIE wafer FIlACEs
1etween the back-hea'l aud the back
connection Of the NVestfield's bDi!er, or
a part Of the leg Of ar ordinary boiler,
ami having the same thickness Uf
plate, and stayed with screw stays,
spaced in the same manner As in tue
cIsc Of tie Westfield; the stays being
one and IN eighth inch i'm diameter,
with the same kinds OF screw threads,
and similar rivetiHg over at the ends.
This structure was set up between two
brick furnaces, and had previously been
subjected TO one hundred aud thirty
eigiIi pounds OF hydrnStatic pressure.
IL began 10 leak slightly when the
steam pressure reached I90 pounds
and burst eXpiosiyeIy from the pull
iag ont Of the stays at lg3 pounds pres
sure. The parts were thrown 10 q
great distance, entirely lemolishing
tie brick furnaces, and leYeling them
with the ground. One of the parts
struck a large boiler in which there
was low pressure ofsteaIa about fifty
feet away, breaking a hole in it eish-
teen inches long and four inches " ide,
fcon which its contents escaped, I'LL
ing the whole fncloseure with cloud
OF steam. Mr.. Stevens had wisely ia.
sisted upon keeping AL the spectators
$50 feet away, and 40 one was injured.
Ia this experiment it was again shown
that an extraordinary pressure il
necessary To rupture even the weakest
parts OF boilers, as ordinarily cOnstruc-
lei-namely the II 1T surfaces; and IL
became fully evident that further and
q ftsFeDt experiments must be trieli in
order To determine why boilers explode
at pres generally lower than these
to which blti these boilers had breu
subjected, or else Ii must be believed
either that tire pUessures are much
greater than has been supposed or ia
difated by eam-gsngPs and sAiety-
valves, or that some force is acting
| upon the boilers not indicated bS the
ordinary metres placed upon them.