US2762136A

US2762136A - Hydraulic dredge ladder

Info

Publication number: US2762136A
Application number: US329213A
Authority: US
Inventors: Bell Leroy
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-01-02
Filing date: 1953-01-02
Publication date: 1956-09-11
Anticipated expiration: 1973-09-11

Description

Sept. 11, 1956 L. BELL 2,762,136

HYDRAULIC DREDGE LADDER Filed Jan. 2, 1953 7 Sheets-Sheet 1 Le'roy Bell INVENTOR.

BY anyway 153M5 7 Sheets-Sheet 2 Leoy Bell INVENTOR.

L. BELL HYDRAULIC DREDGE LADDER HMMH m WH I IM MHHI ww i l l I HUM lllll-ll'lllll l/ll-l ll l||..|I..||lI.|||||||.l.|I|.I.I|l-|l| [III III Sept. 11, 1956 Filed Jan. 2, 1953 Sept. 11, 1956 L. BELL 2,762,136

HYDRAULIC DREDGE LADDER Filed Jan. 2, 1953 7 Sheets-Sheet 3 L eroy Bell INVENTOR.

WW @Mgg Sept. 11, 1956 BELL 2,762,136

HYDRAULIC DREDGE LADDER Filed Jan. 2, 1955 7 Sheets-Sheet 4 Fig. 4

I Leroy Be ,2 INVENTOR.

BY WW m Sept. 11, 1956 L. BELL 2,762,136

HYDRAULIC DREDGE LADDER Filed Jan. 2, 1953 7 Sheets-Sheet 5 F l" g. 5 24 o 172 72 5a 4 104 F g. 7

o 0 so -lae /70 o /02 u //0 1/0 I l Lero y Bell 84 INVENTOR.

WW EM Sept. 11, 1956 BELL HYDRAULIC DREDGE LADDER 7 Sheets-Sheet 7 Filed Jan. 2, 1955 Leroy Be/l INVENTOR.

BY flaw/ 16M 0 H m 0 a F 0 42 8 m. W h 0 4 9 2 I 2 w 4 and United States HYDRAULIC DREDGE LADDER Leroy Bell, Fort Lauderdale, Fla.

Application January 2, 1953, Serial No. 329,213

2 Claims. (CI. 37-67) This invention relates in general to dredges, and more specifically to a hydraulic dredge ladder construction.

At the present time, the hydraulic dredges in use consist of a dredge hull which has mounted at the forward end thereof an A-frame from which extends forwardly a hydraulic ladder. The hydraulic ladder is supported at its rear end by the A-frame and during a cutting operation, the outer end thereof is primarily supported by a cutter head of the same. This arrangement is disadvantageous inasmuch as the entire weight of the dredge ladder may not be placed on the cutter head to facilitate the cutting of rock and the like, the dredge ladder extends forwardly from the supporting A-frame with the result that a cantilever action takes place when the dredge hull is swung during a dredging operation by swinging cables attached to the dredge hull, and the arrangement of the cutter head on conventional dredge ladders is such that the cutter head cuts only when the dredge is being swung in one direction. tI is therefore the primary object of this invention to provide an improved hydraulic dredge ladder arrangement which will overcome all of the above mentioned disadvantageous features.

Another object of this invention is to provide an improved hydraulic dredge ladder construction which includes a vertical A-frame mounted at the forward end of a dredge hull and being constructed to have a dredge ladder movable vertically therethrough, a dredge ladder mounted within the A-frame for vertical movement whereby the entire weight of the dredge ladder may be placed directly upon cutter heads carried thereby.

Another object of this invention is to provide an improved hydraulic dredge ladder construction in which the dredge ladder remains substantially within the confines of the dredge hull and to which swinging cables are connected whereby side thrust is imparted directly to the dredge ladder adjacent the cutter head thereof so as to eliminate bending and other stresses in the dredge ladder and its associated support.

Another object of this invention is to provide an improved dredge ladder which may be lifted vertically through a well in the dredge hull, said dredge ladder and said well being so arranged whereby the cutter head carried by the dredge ladder may be raised up onto the confines of the dredge hull within said well so that the dredge hull maybe floated into position.

A further object of this invention is toprovide an improved hydraulic dredge ladder construction which ineludes first and second cutter heads, said cutter heads being designed to rotate in opposite directions so asto cut when the dredge is being swung in opposite, direc-' tions, said cutter heads permitting a dredging action regardless of the direction in which the dredge is being swung.

A still further object of this invention is to provide an improved dredge ladder construction which includes a support and a vertically adjustable dredge ladder, said support and dredge ladder having associated therewith a vertically movable guiding framework which is telescoped over the dredge ladder and which is positionable within the confines of a well in a dredge hull through which the dredge ladder passes in order to properly support the dredge ladder against transverse movement.

These together with other objects and advantages which will become subsequently apparentreside in the details of construction and operation as more fully here: inafter described and claimed, reference being had to the accompanying drawings forming a part hereof, where in like reference numerals refer to like parts throughout, and in which:

Figure 1 is a top plan view of a hydraulic dredge and shows the general arrangement of the improved dredge ladder construction, other portions of the hydraulic dredge being shown in schematic;

Figure 2 is a side elevational view of the dredge of Figure l and shows the dredge ladder in a lowered position with the cutter head thereof in the middle of a dredging operation, a portion of the dredge hull being broken away and shown in section in order to clearly illustrate a universal joint of suction piping, an intermediate portion of a supporting frame for the dredge ladder being omitted;

Figure 3 is a front elevational view of the hydraulic dredge of Figure l and clearly shows the details of the improved hydraulic ladder and its two cutter heads, also shown is the relationship between the hydraulic ladder and its associated supporting frame, an intermediate portion of the supporting frame being omitted;

Figure 4 is a front elevational view similar to Figure 3 and shows the dredge ladder in its uppermost position within its supporting frame to permit movement of the hydraulic dredge from one place to another through relatively shallow water;

Figure 5 is an enlarged fragmentary transverse vertical sectional view taken through the lower portion of the dredge ladder and shows its general construction and the relationship of the same to the dredge hull when it is in its uppermost position;

Figure 6 is a fragmentary transverse horizontal sectional view taken substantially upon the plane indicated by the section line 6-6 of Figure 5 and shows the general cross-section of the hydraulic ladder and a central portion of its supporting frame;

Figure 7 is a schematic diagram of the means for controlling a dredging operation of the hydraulic dredge of Figure 1;

Figure 8 is a fragmentary vertical sectional view taken through the dredge ladder in the vicinity of the dredge hull when the dredge ladder is in a lowered position and shows the relationship of a vertically movable supporting framework telescoped over'the dredge ladder for supporting the lower portion thereof within hull through which the dredge ladder extends;

Figure 9 is an enlarged fragmentary vertical sectional view taken substantially upon the plane indicated by the section line 9-9 of Figure 6 and shows the general construction of a rear portion of one of the cutter heads and .the arrangement of suction piping connected to the Referring now to the drawings in detail, it will be.

seen that there is illustrated a hydraulic dredge which Patented Sept. 11, 1956 a well in the dredgesame is in a raised poisreferred to in general bythe reference numeral 10 and which includes a dredge hall- 12; dredgehnlt 12 has the general configuration of conventional dredge hulls with the exception that the forward end of the sameis provided with an enlarged well l 'which' is best" illustrated in Fi-gure Communicating with the large well 114 at the rear end" thereof'is a centrally" l'ocated' smaller well 16 whose purpose will" beset fbrtlr more detail hereinafter.

Rigidiy: secured to: the front portiinn of' the" dredge hull 125 and extending npwmdlytherefrom in overlying relation! to the well" I4 is: a supporting frame which is of thc -A-Nframe type and which: isreferred to ingeneral byrtheg, reference numeral The supporting; frame 1% includes a pair of identical halves which are referredftoin: generazlf bythe reference numeral 28 and which, are joined together at their upper ends by transverse frame mernbersrZZL Each of the, frame'halveszh includes a pair of longitudinally spaced angle members 24" which fornn the main frame members of the" frame halves 2i! and which alsofunction asguide members for a-d'redge ladder which iscarr-ied by the supporting frame-18; the' dredge-itladder being referred to in general by the referencenurneral: 25 and will be described in more detail hereinafter:

Each;frameihalf 2t)= also* includes' a pair of diagonal frame members 28 which slope upwardly and inwardly 251-2 adjacent thesupper' ends I thereof; The: lower'endsof the; diagonal frame members-28 are I secured to the lower ends; of the angle members 241 by a horizontal framemenrher: itlzanda supporting gussetconstruction 32. It will be understood that. the; horizontal frame: member 30 lies; directly; on-the deck of the dredge. hull: 1-2'. and is rigidlyasecuredi tonthetdredge; hull'to support the: associated ,anglea' member 24 in' cantilever relation overlying the well 14.. Also. connecting together the angle: meme hers '24 and their associated diagonal frame. members 28::arc diagonal braces 34? and longitudinal bracing13'6, the. longitudinal bracingav being best: illustrated in Fig-- meal The;dredge ladder; 26 is generally rectangular int cross, section and is formed by front and ICfli'Pfiil'S-OfVfiHiCfll f time:menzthersE 318; and: 40; respectively-,: which aretinmthe form; (If-(angle;- members: internesterlwithin angle; members: 24, sagas: to be guided "thereby fOIflVBI'fiCfilZ movee mental Connecting? together: the front; verticah frame members 38 at verticallyispaced:interyals arefiontnhoria zontal' frame: members. 42: which: haves disposedtherehetween. diagonal:,bracing{44=. The rear: vertical frame,- members 40 are also connected together by similar'rhorie znntalframesmembers;46:and;diagonal, bracing 48;

The: dredge ladder 26.- also includes. horizontal: side; framermembersisuwhich conneeti'together; adjacentz front and: rear; vertical-frame mernhers 38: and; 4h... Intercomnecting; vertically, spaced; side frame members 50; are diagonal: braces 52. V 1

Carried by uppermost horizontalframwmembers 42:5 and; 46 are ilongitudinallg aligned; padreyes; 54-, whiohhave connected, thereto: lower; ends; of". lifting; bars 56". The:

. upper; ends; of the liftingbars 56; are connected: teat book; of; a. traveling block ;5 8,"WhiCht iS connected: by=-an:.

V and' which are secured to theirre spective angle-members ber 78 is al'scr'bracect intermediate its endsby' depending vertical frame members. 801* which are. secured to the lowermost front horizontal frame member 42.

Carried at-the lower end" of 'the-dredge ladder Z6 and supported by the transverse: frame:

members

74 and 78 are cutter heads 82 and 84. Referring now to Figure 5 in particulan'it is seen that the two cutter heads 82 and 84 are identical, with the exception that their

individual cutting blades

86 and 88, respectively, are curved V in difierent directions and" are designed to cut" effectively wherr'the' cutter heads 82 and'84 'are rotated im opposite directions. The purpose of the difference in the blading ofthe two' cutter heads will be explained more detail hereinafter. V I

Inasmuch as'the two cutter heads82 and 8'4 are identical except for thearrangement oftheir' blades; only one: of the cutter'head's, the cutter'head 84- will be ex,

pl'ained in detail. Ae is best illustrated in Figure 1 0;

- the-cutter head 84 includes a rear main cutter 9'0 =a'nd'-" a= forward-auxiliarycutter 92; The rear main cutter 90 includes a longitudinallyextending snpporting shaft 94 which is-rot'ataoly j our-naled in suitable pillow blocks Vdetachablysecured to the lowerside of the transverseframe members 78' and 8tlg. the pillow blocksecuredto the transverse: frame member 78 not being tillustratedi The main cutter 90,- whi'ch is'-* disposed between the transverse frame'members-fi and 78; includes a plurality of 'longitudinally extending blade support's 98 whichare secured to the shaft 9 wby a: plurality of longitudinally spaced spokes 96; It: will benoted' that the spokes 96 are disposed only in the-forward halfofi the maincutter' 905 Carried by the blade supports 98-"are' suitabl'e spiral cutter blades" 88 which have been: described 'in more} 7 detail abovea elongated: cable: fitlt'o; a crown: block:62.= The crowns.

blQCks 62-. is, suspended; frorrrv a cross beam: 64lrestingr: upomand secured tozvuppenhorizontalg; side: frame members 66 which connect together: the: uppenendss otfthei angle: members. 24 of; each. frame; half; 20; A, free end otgathei ble 6D; extends-into; at deck: 1191156268 of: the; hydraulic dredge 10 and is reeledupoma drumz'lflrofr ae 7 adiacentrtheir lowen endsiis anenlargedgtransverscftame 4 member 74. The transverse frame member 74 is bracedby: arpair of V intermediatesyertical' frame members; 76

In: order that the maimcutter may be 'conveniently rotated; there; has been 1 rigidly: secured to the rearrpon- V tionst of fll'ei blade supports 98*. a i drive :pulley 1 00'.- The driive: pulley 100 has: entrainedi there'oven afi drilve' chain 7 102 ,whosez-uppen end:. is; entrained: over a: driver pulleyra 10.45which:is-carriedtby a:.driveishaft of azreductioni gear box :'1=06:. The: reduction gear: 130x106 upwardly? conr nectedtt'o arpower'source'gasuchz as an internall combuse tio'n: engine?v 108; the: reduction gear box-1' lofiiand that: interna-licombustion: engine 108 being; supported: hyt: uppermostzfiame membersrotthetdredgesladden'lflt as; the drivespulley 100 .isrdisposed;.slightl3a outawardly of the confines of? the-idredgec ladder 26;: there:

is-tcarriedxhy an associated: lowermost side-frame: memben'50' an idler: pulley: 110:1 As iszbestill'ust'ratedrimn Figured} the: idler pulley till-urges the: dr'iverchaimim wardly; as: it: comes; ofi-.its-'v associated: drive? pulley- 100,:- 50: as to: he: disposed.- within: thccconfines. oiiiithe; dredge laddenz2fizi The forward end of thezshaft 9451's reducedzandpolygsonal;in:crossasection:;aseat:11% ldigidlyimounteda on the.

'rediuiedr:portionv 1 121 of: the:- shaft 9.4 f0fi rotation thercs=- witlriis a hubi 1 14;. therhub 1 1345 being-secured OlIiIhBS reef duc'ed portionmf th'e shaft- 112 by a locking member H6:

The huh 114% is part; of the:auxiliary"cutter 92 andlhas suppc artetlthereby:spirahcutter blades- 118a i Secured tattle-front face of the transverseeframetmema V rearplate 120 which encloses theupper porti" nto'fi the main: cutter 905 Extending": into the; lower ber 74 in a manner best illustratedvin Figure 10 the 1 main cutter; 90 rearwardly offihe rearmostsmkbx-QSL is a suction inlet-pipe ltkz whicht-is supportta'dihy; renter

able yokes

124 and 126 secured to the bottom and rear of the transverse frame member 74, respectively. Carried by the inlet suction pipe 122 and closing the bottom portion of the rear of the main cutter 90 is a lower plate 128 which has passing therethrough the inlet suction pipe 122.

Referring now to Figures and 6 in particular, it is seen that each of the inlet suction pipes 122 includes a horizontally disposed section 130 together with a vertical suction pipe 132 to form a Y- fitting. .While the yoke 126 does aid in the support of the suction inlet fittings 122, it will be noted that it is actually connected to the suction pipe 132 for retaining the same in a vertical position.

Referring now to Figures 1 and 2 in particular, it will be seen that mounted within the deck house 68 is a suitable rotary pump 136 which is provided with an inlet 138. The inlet 138 is connected by a universal joint 140 to a first generally horizontal suction pipe 142. Telescoped within the first horizontal suction pipe 142 is a second horizontal suction pipe 144. The second horizontal suction pipe 144 is connected by a universal fitting 146 to an L-shaped upper end of a vertical suction pipe 148. The Vertical suction pipe 148 is connected by a plurality of intermediate telescope vertical suction pipes 150 to the suction pipe 132. The rotary pump 136 also includes a discharge pipe 152 which may be connected to suitable discharge pipes 54 which extend over the stern of the dredge hull 12 and may either lead to the shore or other points 'of discharge.

When it is desired to elevate the dredge ladder 26 so that the cutter heads 82 and 84 thereof are disposed within the well 14, it will be seen that it will be necessary to telescope the

suction pipes

148, 150 and 132. Inasmuch as the length of the pipes when extended, as compared to their combined length when telescoped, is by construction greater than that of the extended length of the dredge ladder 26 as compared to its elevated projectmg length, it will be seen that it is necessary for the upper suction pipe 148 to be elevated in order that the dredge ladder 26 may be elevated to its uppermost position. In order to assure vertical movement of the upper suction pipe 148, it is connected to a suitable guide way 156 carried by the rear portion of the supporting frame 18. Vertical movement of the upper vertical suction pipe 148 necessitates the

universal fittings

140 and 146 as well as the

telescoping suction pipes

142 and 144.

As is best illustrated in Figures 1 and 7, the hydraulic dredge has also mounted in its deck house 68 a pair of

winches

158 and 168 which include

drums

162 and 164. The

drums

162 and 164 have reeled thereon ends of swinging

cables

166 and 168, respectively. The swinging

cables

166 and 168 extend from the opposite sides of the hydraulic dredge 10 and have their other ends anchored to suitable dolphins 170 and the like. I

The swinging

cables

168 and 170 extend upwardly from their

respective drums

162 and 164 and are entrained over suitable sheaves 172 carried by an upper rear portion of the supporting frame 18. The

cables

166 and 168 then pass downwardly through the supporting frame 18 and the dredge ladder 24 and are entrained over lower sheaves 174 carried by the rear vertical frame members 49 adjacent the lower ends thereof.

Inasmuch as it may be undesirable to disengage the

cables

166 and 168 from their respective sheaves 174 while moving the hydraulic dredge 10, the dredge hull 12 has been provided with suitable recesses 176 in the bottom and inner side portions thereof adjacent the well 14. The upper portions of the recesses 176 include curved plates 178 over which the

cables

166 and 168 pass to facilitate sliding of the same.

In the normal operation of a hydraulic dredge, one of the swinging cables will be payed out while the other is taken in at the same rate. This causes the swinging of which are connected the entire hydraulic dredge in one direction. Inasmuch as the cutting blades of the cutter head of the hydraulic dredge should be drawn into the material being dredged, and since a cutter head can only cut in one direction, it will be seen that during a dredging operation with a conventional dredge that the dredging will be done in one direction only. This results in a loss of time by reversing the paying out and taking in of the cables to swing the dredge in an opposite direction to start the dredging operation over.

In the present hydraulic dredge, the hydraulic dredge 18, the provision of two cutter heads 82 and 84 which are designed to rotate in opposite directions permit the hydraulic dredge 16 to perform a dredging operation regardless of the direction in which it is being swung. When the hydraulic dredge 10 is swung to the right, as viewed in Figure l, the cutter head 82 engages the material to be moved and the same is drawn rearwardly through its associated inlet suction pipe 122 due to the action of the rotary pump 136. During this time the swinging cable 168 is being taken in while the swinging cable 166 is being payed out. When the end of the cut is reached, the dredge ladder 26 is lowered the desired depth through the use of the winch 70. The cutter head 82 is then stopped and the cutter head 84 is rotated simultaneously with the taking in of the swinging cable 166 and the paying out of the swinging cable 168. In order that material cut by the cutter head 84 may be drawn into the rotary pump 136, a valve 180, which is best illustrated in Figure 9, controlling the flow of material into the lower vertical suction pipe 132 from the pipes has its posiinlet suction pipe 122' tion reversed to communicate the of the cutter head 84 with the rotary pump 136.

Inasmuch as the cutter heads 82 and 84 extend outwardly of the confines of the dredge ladder 26, it will be seen that the well 14 has a width greater than the width of the dredge ladder 26 to provide clearance for the cutter heads 82 and 84. In order that the dredge ladder 26 may be supported against bending movement at the extreme bottom of the dredge hull 12, there is provided a framework which is referred to in general by the reference numeral 182 at each side of the dredge ladder 26 and the sides of the well 14. Each framework 182 includes a vertical guide member 184 disposed adjacent the front and rear corners of the dredge ladder 26 at its respective side. The vertical guide members 184 of each framework 182 are connected by a horizontal member 186. It will be noted that each of the guide members 184 includes a vertical guide way 187, in which is disposed a vertical guide member 188 carried by an adjacent side of the well 14 and projecting inwardly thereof. It will be seen that the guide members 188 guide the frameworks 182 in their vertical movement.

When the dredge ladder 26 is in a lowered position, as is best illustrated in Figure 8, the frameworks 182 are disposed adjacent the bottom of the dredge hull 14 and are suspended from cables 190 connected to eyes 192 carried by the angle members 24 of the supporting frame 18. However, when the dredge ladder 26 is in its uppermost position, as is best illustrated in Figure 9, the frameworks 182 are raised upwardly out of the Well 14 to provide clearance for the cutter heads 82 and 84. In order that the frameworks 182 may be moved upwardly upon upward movement of the bottom of the dredge ladder 26 into the well 14, there is carried by the

vertical frame members

38 and 40 adjacent their lower ends outwardly projecting stop members 194. The stop members 194 engage beneath each of the vertical guide members 184 and urge the frameworks 182 upwardly to the positions best illustrated in Figure 9. Thus, it will be seen that the dredge ladder 26 may be supported the full depth of the dredge hull 12, and at the same time, there will be provided sufiicient clearance for the cutter heads 82 and 84 of the dredge ladder.

Referring now to Figure 6 in particular, it will be seen the full? weight of the? dredge: ladder maybe pl'a'ced'upon the cutter h'eadsi oft the: same to: provide more efiicient cutting. Also, it will be seen that the swinging cablesof: the: hydraulic dredge" are; connected directly to the dredge ladder adjacent its lowerend: s'othat thesideward thrustupon the cutten heads: will be imposed almost directly at theinpoihts ofiisupport so as t'o eliminate bending StIGSSCSiiE-thfi' dredge la'dder other than those imposed' by: resistance of the? dredgehulli to sideward' movement througlr the: water; Also byproviding two cutter heads instead: of the customaryr one;-.it=-is seen that a dredging operation may be=.continued1 regardless of the direction inwhich: the dredgeis beingswungi In the actual operationrof one of the cutter heads, the auxiliary: cutter. 921thereofwill penetrate the deepest into arock; or thelike formationiand-urgeparticles of the same back-to the main cutter 9,0 which operates in anormal manner, hollow center willthen suction pipe 122 direchthecuttings into the inlet rock; formation, it- Wlll be seentthat no rock will be cut inthe space between the maincutter 90 and the auxiliary cutteru92.- Inasmuch 'as this rock would be engaged by one of the front vertical: frame: members 38, it will be seen that in the caseof aerelatively soft rock, the-front vertical'frame member will cause the narrow portion of rocks left between t the 1 two cutters to breakofiand pass into themain cutter 90iv However, inrthecase of extremely hard rocks, the pressure exerted by the 'front frame memtion, Inithis case, it=mayj be necessary to provide outwardlyprojecting-teeth (not shown)- on the front vertical frame. member to causeraslifting action upon the rock formation to break the: same up; 7 g It will be understood that the controls for the improvedhydraulic dredge whichhas: been? disclosed above' will be substantially,

and only minor changes willrbe? necessary in' hydraulic those skilled intthe art it isnot desired to limit the inventiont to the;exact .constructionshown and described,

Theim'ain cutter 90,1which is provided with a the sameast thatof t conventional dredges and accordingly, all suitablenrodifications and equivalents may be=resorted tOZiaIling-Within the' scope of the appended claimst r .v I 1 What: is: claimed: as new is as follows:

a l. A hydraulic dredge comprising a dredge hull, a dredge laddermounted at one end of said dredge' h'ulL-a' cutter he'ad'at' the lower end of 1 said dredge ladder,- s'a'id ladder extendingivertically, said' ladder passing through anopen well: in saiddredg'e hull, a: framework telescoped' over saidtdredg'e ladder positioning sai'd dredge ladder Within Said we'll, saidladder being-.mount'edin z'i vertical 1 frame carried by said dredge hull, said framework-beingii v suspended from said'vertical flame, stop means on said dredge ladder with said framework-man'upperposition of. said 'dredge la'dder fdrelevating said framework with said dredge ladder.- n 1- Q 2,. A hydraulic dredge comprising a dredge hull; a dredge ladder mounted: at one end-of said dredge hull, a-

cutterhead} supported by the lower end of said dredgeladder, saidladder extendingvertically, a-w'ell in said dredge hullopening through one end.- of said dredge hull,-

associated therewith." In the case of a said ladder passing-t through-said open well; a framework telescoped overs'aid dred-ge laddenpositioning said dredge" ladder within said wella vertical frame carried by said 1 dredge hull, said ladder: being? mountedin's'aid verticalfra-rne,.said framework being suspended fromsaid vertical frame, stop meanson-"said dredge'ladder engaging said framework in an'upper position of said dredge ladder for elevating said framework with said dredge} ladder; means for vertically adjus ingesaid drcdgeladder, pump means? carried by saiddredge hull tsuction piping== connecting saidfpurnp means to; said cutterhead, said pipingincluding"e vertically telescoping-r sections extending within said-.7

ladder, a-lowermost of said sectionsbeingqigidly secured to said cutterhead, an-uppermostofi saidsections'being guidingly, connected tosaidvertical'frame.

' References Cited-in the-file of this patent" UnrranfsrATEs' PATENTS 185,600 Von-Schmidt" Dec. 19', 187 6 328,09 5- Wa1sh- Oct. 13, 1885" 355 2-51 Bowers Dec. 28, 1886 401,896 McFarlane Apr. 23,:1889-1 477,82] Southen. June 28; 1892 601 524 7 Parker Mar. 29, 1898" 629,910 Nichols Aug. 1; 1899" 735,255 r Gillespie Mar. 28;1905 1 992 692 Newman Sept.- 5, 19-11 1,0- 19 ;6 1 0; Donnelly 19-12.- .6; 9.; Cas y 1,713,037 Ellis