Richmond enquirer. [volume] (Richmond, Va.) 1815-1867, 1857-01-27


l-1cth ui drttwav.
Ii NAV he wcll 20 close tn. description Of this Tun
No.. by giving summarr "f .he leading features Z"
th" preceding -tstemrn;:
L'urth Of Tunnel, 2si &.
Dimensions OF Section, II Il. hi,;h and Ia whir.
Dimensions stched, iUl II.
Cube curisut-, 3Q,CpV cubic yhr1f.
Cu"lr contents per liresr f.. III
Cubic yards mseoury laid, 2,'al cubic yards
INCLINATION. of grade, 20 Il. Per nile.
Total cost Siti,Un0
Cot per linear H., ltS
Total coet per cubic yd. oo
Cos; ps- eScavstinn Gloue. UO
Time ot construction years.
Next to III. Gres; iunnG: ~ point OF magnitude
and far exceeding it m hs difficulty ol its c0nst!u"
ii"u, is the Biooksve Tunnel, a!lch pas,es :h'onSs
projecting spur Ci the main mountain about ihte:
miles Ess. Oi tho Great lurnr lti irngth Il only
SlsS feet, and the height ui the spur above IT. Is
feet. Nc unusual difficulty % ioreae-n i'll lis coh
structon; IN fac: easy task waa anticipated hot
by iho i.nsinrp. aad ihe c0n;rac."r;-yet OF :,
trencSsrou5 Ls:uTO is III. rock encountered. that
proved difficult an undertaking ci the sori rs liz
ever been achieved IN this country. No ons who ha
not THE work in the various stages OF It's pro
9ress, cnn vel. appreciate ths u;rIng industry nn'
perseverance, which hSs been d. played hsre. Il
gresest credit ID cue To tho contractor, MIR. JOIN
Kelly, for his faithful execution Of the work. aud hI
courage 80 often displayed at trying times.
The Eastern approach 6f this Tunns Is al sIcHra
lion 81 ;ret in depth u rock al nearly hard anGtnr
d. that found III the main mountain. sGd thronGh th
material l5 g. OF the Tunn"l a perforated Blu: herr
al abrupt change occurs and the pertoratinn passe
into rotten state lying OF au anglo about trans
vsrsry TO the Tunnel and scanned in al directions.-
Tho slightest disturbance from q blow or bias
would soTeiimes bring down avnlancbRs ot rocf
into the Tunnel leaving in.ueDse cavities shove I.
bo died with packing OF proprsd with timber Thl:
character OF r0ck cou'inurs throughout tho rsiuGu
a, = a T,t, "a prl afr. .fn,i
cou,laono,d d on te W.s'rru side. snd although mrci
.rsi sc.L than was anticipated before opscng, ail
:htrc wa. thought 10 Gc suiGciaDt cohesion III tb.
material or the drst ir% f'et driven. sme!i crGck-
however, econ began 10 gpp"s! apd ihe roo! VIZ
partially e'rr-d 6y vertical p.ops NJ rough timber
lis appearance continued - ;t0T st! more alarming
notwithstanding ihis p.ec"rti"n nnd NJ i-0gih 'srg,
crack became visible IN tha face ri lu 'xcaTsriou
ou.Sid. ol the Tunnsi ana sbuIi twenty ie"t shove
IN. eEtrauce--si 40 .idIuS or failing had tah or
plnca. Il nov deirrii med To Introduce n more
sys!snsrin Node of support, Hrd poiygons, frames ~
rough iiinrsr u !u;iiv- in diarrt-r norr, w.r;
p!srri a. Intervals OF eight fest II thought ,ha,
with th. Gsa;stancs The rnCi would stgud nh. The in
'.odaction of brick arch This ercI would havs bee
Immediately introduced il brick FOR the purpose had
brr!, al baud but The nrcrs'iiy them having
been anticipated UoI+ could be cS!ainsd Immediate
!y.
l. We, perhaps fortunate that this WAS lhs case: inr
Tho rock not yr: having rsbited its worst features
su II slight tor the purpose might have brer
introduced sud cssuli!oud consequence. have eu
sued.
A.. ,ha perforation proocsds tha difficulties ia
craaad lsrgs siidra apd iui,s took place. thorough
timbers were r-piaoed by large sq'iated on"s,
fully ipinrad and brac-d, the !reins9 We're placed
ony tour frrt apart, snd !!ie aparss hsiTr.n tiien
supported oy longitudinal TIMBER. altogether form.
ins probably hs stron9Si: timber lining Gvor used
for such pur2nasc. The h.sdirg We= driven Ia this
way .or five hundred feet, snd !. was then deter.
mined - sxGsrefe the button course "a soon as
brick could ps prW urrd !ur ,hU purpose Of lining.
Tho very heavy tinEerDG used aid rot prove sut-
Scient for the weigh: upon II, snd considerable
length about midway OF The tunnel, and under the
highest Point o! he -pur iel In. crushing ;hr heavy
huk. into fragments, sni cl0suS Tho dri!tway ~ith
ihu iejy!s. The TAX uns appeared almost hopeless,
ali we're discouraged, .nd Il was with gres difficulty
ihH. IaeH could 5e induced 20 work in q place 60
threatening.
A: length, homever, all msteriai5 being prepared.
tia work resume t. edGIt'DnnI tirnb.rs werc In.
serted HhcTs rsqp d. the bottom was STACKED
and fast rs il was removed, The srciing intro
iuood Ia tho Tneanri7 thar ,r,i1n cfths root ~hoh
had fniur i'll oeors stated, continued to give way,
and a, !eSgt tEe shJe in lending iG.,s in in 20 the
top in Two pscns. fcrgnrG a4 il wrre Two crs'-rs some
50 feet sdrara OF IN. surface, a1l So.ln $50 feet in
dsrth /, was touht necessary 10 remove nearly iL.
whois oi thu con'en If IhDse cavities through the
trnnr, into which they AradGa,i; dssnrnd.d ~
through 4 iUnnrl. during The removal. W Nhtu this
wss dnns massive timber ron! va: constructed A. a
pnectio2 - tho woszme.: irrn fcttker sl'iee, and
the srnh Inserted as EoOG Hs pi:s!b.1 SIuce this much
more hsa fallen upor the arch, which. however, "a
sufficiently strong 70 bear any weight thus brought
upyu il, and the trains ara noS passing through the
tunnel III security.
The construction of this ;uInel u:dsr sao Gircu!n.
s.6nCas has Of cnurae b-en very costly. Through
material Z, hard ca ;hst c the g!ast tunnai i. ond
have been tiuch less: proving tia. the hardest
material j. not by any means 81 g!eas a n5sthcr to
thH work Of tunneng, as that Of a irehc.erons OF
doubtful Gharaairr, hnwer+- aaPy OF "Zcnrat!on.
rh. cost 6t this WORK incndiug oil CHARGE
amounted 10 ella 800 which is at The rae of 49,
psr l. foot. Two live. o-t during the execution
u this work ia consequence al tho iaii OF large aI
rncnt of work near the entrance.
The Greenwood Tunnel ti.oash spur of the
mountain about miles below the Great Tunnel or
the seass.a edo, is 5s :oa; long I, presented di
cnlta- sly equal TO those overcome at The Brook
vile Tusuel, Bat having been undertaken after thai
work had begun, precautions were taken which ex
pcrencs had shown tha necessity for. IL was success
tally accomplished Without :hs l"ss ots single lite. and
has u.cn ia use lor time. IL ID linsd with avery
thick brick arch throughout s lsu sh, ant massive
ror,s ot the same material constructed nj each
nd Tho total cost wa 216 4uU which i. at the rate
vf sli2 per foot. M less 'hsu q 600 cubic feet %
tim ber and s!i Uj0 brick were used IN its eIeou
tioB
An exfact from report Of Colonel Cro1st to the
Board nf Public WORKS. losie daring the construc
ton Of this work, 1i! give come Idea OF the diihcu
tie1.
"On the 9Th section all that remains to be done is
the third tunnel. work OF The utmost dhcu!ty, aud
Certainly one Of Inc worst cases Of tunnelng on rn
cord Tho perfora,ou IL ihrou2h rock hard enough
10 require blasting, but full nj assures, and which
By the contact The air, very soon hec0mes ifabie
snd woI.d slide in large masses uni1's SUSTAINED
overhead and latersliy by sufficient propping. Iht
operation OF undermining the frames by which the
-. .d in rhn Eahiuy IL not 0uly teu
ous but a;tsnGrd with considerable danger; the aides
being insecure for the support Of lhs npper iraInsh
resort has been had 10 plan by which ;he cnts'
frames are supported by tha Interior ones with tht
assistance of balance beams d.taned 10 tbs cross ts
Of the l,tsr. II IL at both entrances tha
the danger was Inost imminent the western lace, al
ter ssv6ral dangerous Slides exhibited 'front.' with
large rent clear ACROSS under which lie dt'acDso
masa depended altogether fur support oh the mrs
frames Of The beading. which begun 10 ,Gcllns out
ward and threatened 10 turn over. Cnder these cir
outustancss the men employed abandoned the worh
twice and were discharged, bnt the energy and per
severance of the contractor, MIR. John Ne'ley, trl
umrhed a, last ths din ,ul'y. AT one time ~
could be secn with only bic clerk and carpenter, en
gagged in securing the impending mass from taTihe
motion. Thus were neu encouraged and recalled "
this work. Thi, end ia now safe, though tue aIcf
lust under the face he heavy loose maze before
Described at iirsi slightly compressed, but III
Tected its top TO be loaded anu well pacSod and noa
aTcfythiDs 10, 10 iii A0PSaieuce-i P'. .u''' "
cured. "
"Atthe ea.tsru sud three successive slidcs OF th'
front cv-cd each lime the srlranco, and made II ne
css.sry 10 trim up be iaoe anew TO al increases
kright ihsreby sdd:ns a nor, 10 each casa, 10 TN
tendency 20 a!iGe Since the last Glide hs. been re
moved and The lace trimmed up cncs more, 1t eI
hjtits, up 20 a height of about ono hundred ieet,
very thrs atyning appearance, ard have telt sres
anI!sty t. ieys, i. this eHd slso. the poris raises
and covered. Much ac'iity vac therefore necessar,
o effect mi. desirable Object before ihe anticipate
interruption by iru.,s which might !7sv" the ~ori
eIpossd dnrins the winter to 'sorss accidents. u
for this purpose that nod tn nas br>k nieTfee 10
the second unaal, tbs contractor Tor the orlck OF IN
third having failed, TO considerable extent 10 iur
nish the requisite receivable quantity Ills - To-
reason eavstted to above fs. susPeld!ns thu archn;
of tho second. all the energy apt available nesns be
attendance and direction OF Mr.. Kelly, Il is yer,
gratifying, l.deod, TIA: the operation has proGre.s.'
sriai, dfoaltie. Of such magnitude wiihou; any ac
oiI.nt, thuucb on-e the men had barely time TO saw
,h.r.,ir.. ron, h.iog or.-Sheltcsd 81 the ava