DG RANJANGAON GROWTH CENTER. M and R to Water supply schemes at Ranjangaon. Strengthening of Bridge walkway, traction and suspender assemblies and flocculation clarifier tank structure etc for CLF no. 1 and other misc works at Water supply scheme, Ra

1) Dewatering   the   excavated   trenches   and pools  of  water  in  the  building  trenches  / pipeline trenches, well works by using pumps and  other  devices  including  disposing  off water  to  safe  distance  as  directed        by Engineer-in-charge     (including     cost     of machinery, labour, fuel), etc. complete. (Bd-A-9/261). (i)  The  Contractor  at  his  request  may  be allowed   to   start   construction   of   masonry steining  so  as  not  to  allow  silting  of  well  in oncoming    monsoon    and    while    paying masonry,  25%  amount  shall  be  withheld and released only when excavation to the full depth is completed. (ii)  Dewatering  :  Total  dewatering  charges are to be proposed in the tender as lumpsum amount  and  75%  is  payable  for  excavation and 25% is payable for construction of well / gallery.  Out  of  75%  excavation,  break-up shall be as under 25% for last 1 M depth. 20% for 2 M depth which is just above last 1 M depth. 15% for 2 M depth which is just above last 3 M depth. 15% for the rest of depth from water table level. The   above   conditions    will   restrict    the tendencies of agencies to avoid deepening of wells, etc. to the required depth.

2) Dismantelling complete old CLF. Bridge walkway assembly, inner suspender assembly, outer suspender assembly, flocculator assembly, traction drive assembly and all other sub-assemblies on temporary support and removing old worn out, corroded rusty parts and stacking the scrap with in a lead of 100 mtrs.

3) Repairs to mechanical flocculator drive assembly by replacement of faulty gear box,faulty electric motor, base frame. Replacement of corroded worn out m.s.Paddles ,shaft, paddle arms by new m. s. parts of higher sections and retaining existing paddle geometry and strength. All the new steel parts shall be painted / galvanized.

4) Repairs to traction drive assembly :-All m.s. parts such as base frame, trolley assembly :- New end carriage assembly consisting of a sturdy M.S trolley with required degree or curvature suitable for smooth circular motion of the bridge walkway and a independent drive assembly consisting of worm gear reducer of adequate size and capacIty driven by a three phase electric motor of adequate rating and power, interconnected by C.I. couplings and finally transmitting motion to traction wheels via chain sprocket assemmbly. The drive assembly shall be mounted on a sturdy base frame fabricated from ISMC 100 x 50.The traction assembly shall have 2 polyurethane coated wheels, the shaft of the wheels shall be provided with self align bearings housed in cast iron pedestal housing. The drive assembly shall also be provided with suitable chain drive to derive necessary speed. (all M.S. parts such as base frame ,trolley assembly shall be painted / galvanized

5) Repairs to central bearing assembly and central turn table : -This item includes supply of new central bearing assembly consisting of imported thrust bearing having adequate vertical load carrying capacity of not less than 2.5 ton to carry the vertical load of the equipment and two radial ball bearings to counter the radial load of the walkway. The bearings are housed in a bearing housing fabricated from high grade seamless pipes specially used for manufacturing heavy duty bearings and high carbon steel plate having high shear strength properties. The fabricated housing is machine on high precision lathe machine and cylindrical grinding machine to close tolerances required for press fit of N9 grade. The housing along with the outer race of radial ball bearing shall rotate where as the inner race of the bearing shall be press fit on a spindle with plate .The spindle with plate is fabricate from high carbon high chromium steel machined on high high precision lathe machine and cylindrical grinding machine to close tolerances to achieve n-9 finish. The bearing assembly is also provided with hinje pin joint to cope the misalignment caused due to level difference if any between the traction path and central shaft top. The central bearing assembly is welded to a base plate or a foundation plate which is firmly anchored to the central column. The bridge walkway is supported on the bearing assembly via a sturdy central support frame fabricated from m.s channel and angle. The central support frame / turn table and all other steel parts shall be  painted/ galvanized .

6) Repairs and strengthening of bridge Walkway : - Replacing all the corroded and worn out parts by new m. s. parts bolted by G.I. hardware the bridge walkway shall be designed for self load,flocculator load, the suspender load and live load confirming to IS.The walkway shall have a width not less then 1.00 Mtr and shall cover full diameter of flocculator on both sides of the central shaft and extend up to the outside diameter of the clarifier tank. The walkway shall accommodate two numbers paddle type flocculator assemblies suitably located on either side of the central column. The walkway bridge shall be supported on two supports only , one at the centre of the tank on the central brg. Assembly at the centre of the tank and the other on the traction trolley on the launder beam. The walkway shall have m.s railing of 1 mtr. Height on both the sides along its total length. The walkway shall be covered with chequered plate. The entire structure shall be sand blasted, pickled and then painted/galvanized

7) Repairs to inner suspender assembly in flocculator tank : -providing ,erecting and commissioning new inner suspender assembly consisting of framed structure fabricated from m. s. structural steel such as angles and channels of adequate size and section, The entire structure shall be Painted/ galvanized icluding bottom scrapers 6 Nos.

8) Repairs to outer suspender assembly in clarifier tank :-Providing, erecting and commissioning new outer suspender assembly consisting of framed structure fabricated from m. s. structural steel such as angles and channels of adequate size and section. The entire structure shall Painted/ galvanized .icluding bottom scrapers 9 Nos.

9) Electrical control panel : - Replacing the old electric motor control panel by new electric motor control panel.The electric control panel shall be a cubical panel fabricated from 16 swg C.R. Sheet with powder coating. The panel shall consist of a main incomer in the from of 32 amp MCB., 4 16 amp MCBS as isolation switches, 3 DOL motor starters. All the parts in the panel shall be interconnected by copper wire.