HomeMy WebLinkAbout1991-05-13 91-196 ORDERti
Date y5-13-91 V Item No. 91-196
O DIM, Autluriaiag the City Mmmgec ro Issue Bids for the
Item/Subject: Turohese of a GfenTole Boa/Cseairim n.nte-rt..., fox
Senex yund avt rtthe Transfer of Flask for
ble Department: Thal Parpoee
flex
ponzi>ress
Commentary:
State Most Federal re9u1at:.,... bnna eatzflb letl Stricter atazdazds; rwgaxdfmg
msavetdon p..�to. 11aepe .vg.:.a.mra are spelled our fn the ettacl i
somoxarsLml
front M:lc Percy, Bmex MairltHianCe Suparvimr. � xeguletSors also
pawdde greater safety for cur mploimang win cork in
The Mtacbai Orden: would a[3uo x issuvy bids fmc a maNnlea Dart And autMrtve the
transfer of existing And evedUebla funds; free witldn Hct operating budget of t va
Sever Itand for this purpase.
i4udcipal Opecatiae has revised and apprrnred.
Oep/mvrm Hare
Manager's Comments: j t -W. Q _ / �py�
6'It07
L
Associated Information:
Order, Memorandum
Budget Approval:
Fin ttOi
Legal Approval
city soliaimr
Iced For
ntrpassage
❑First Reading Par —of—
❑ Referral
91-196
Aeaiped MC Hor Bragg, May 13, 1991
CITY OF BANGOR
MnU 1B/rbtr, .. Aat riaiuq- aty- to issuelY&..for-ure-Puxcl�ew
f a [4Nnle Box/ tib Pcofa[irnr fax: t Beast rivet mtl AUHbaiain9 Ue
Txmafer of Fvvla fox this F¢mee
By alp Caun of W My OfBargor:
ORDERED,
THAT
the aty Manager is hereby authorl to solicit bids for the
Of
xePflix/xepl�� of venMlee otMt sw ll m¢:ava i .
2E = FIIf6a+R OItOERBD, TIWT the transfer of $11,000 f2ml Acmalt
Mnobex 80-01-07.05 w A:munt lamiter 80-0}10.02 is autiarim for this putpoae.
In City Council MAY 13, 1991
Passed
4IA�
qty ar
91-196
DR DER
Authorizing the City Manager to
Issue Bids for the purchase of
e me Mole b�ay�....svatlan protection
for the se riw and authorizing
............ se
the ,trade of funds P t
QQ 9W
........ Ae®pied to
"UGowcilzan
91-196
TO: City of Bangor
Municipal Operations Committee
COPIES: Ed Barrett. Her.
Dave Pelligrino, Purchasing Ppent
Dave @uartararo. Finance Director
Ralph Mishou, Treatment Plant Superintendent
John Frawley. City Engineer
James Ring, Public Works Director
FROM: Mike Perry. Sewer Maintenance Supervisor
DATE: April 25, 1991
SUBJECT: Manhole Sox / Excavation Protection
Effective January 2. 1990 the Occupational Safety And Health
Adminietratlon (OSHA) amended its construction standards for
excavation and trenchinq. More strict regulations have been
adopted regarding shoring and protection against c
Sloping or shel.vXno, utilization of a pre-engineered manhole /
trench box orshoring system, o site design and construction
of a support system are the three options available to crews
volved in preforming work below grade. For most of the work
performed by Public Works end the Sewer Department it is not
reasonable to design and construct a sharing system. Even
shallow excavations of s' to 10' feet require large amounts of
heavy (6" x 9•and z" x 6•') timber bracing. This is extremely
time consuming to install and much of the timber must be out to
fit thus making it expendable.
Shelving and slopingiable options under some
conditions; however type a@ s
Coils (of which most in Bangor are)
require a slope of 1.5 horizontal to 1' vertical. This i
workable for very shallow excavations. For example a 5' deep
trench with a 3' wide bottom
would require a excavation IS'
cross. A SO' deep excavation with a 6' wide bottom (required
for manhole replacement) would be 36° across. Not only 1s it
time consuming and costly to excavate but the a material
often makes it impossible t0 do without disturbing areas outside
the traveled way or working easement. In the above example a
excavation 10' deep would require removal of approximately 190
cubic yards Of material and 145 square yards of pavement.
91-196
If an 8' x 8' sq. manhole / trench box were employed it
would reduce the volume of excavation from 3.90 cubic yards to 24
cubic yards, a reduction of 87%. and disturbed pavement from 144
square yards to 7.5 square yards. Additionally utilizing a
trench box minimizes the disruption to other subsurface
utilities as well as maintaining vehicular traffic.
For the above mentioned reasons it important that the Sewer
Maintenance Department Purchase a manhole box. Many of the
projects we aYe n
involved i mall point repairs or manhole
replacements. Projects ofthis nature require the U$e Of a
mall rubber tired axcavatpr with limited lifting capacity.
Total weight of this unit should not exceed 2500 lbs. This
weight requirement can only be met by an aluminum box.
The estimated cost of this box $11.000.
Micheal A. Perry
Sewer Ilaint. Supervisor