Piling rigs

A piling rig comprises two sound-reducing enclosures arranged one over the other. In use the bottom enclosure is arranged around a row of piling and the top enclosure surrounds the piling hammer as it moves along the row of piling for pile-driving or pile-extraction purposes.

The present invention relates to piling rigs and in particular to piling 
rigs including means for reducing the noise emitted from the rig during 
piling. 
Piling rigs have already been proposed in which the noise emission is 
reduced by enclosing the pile driver and at least a part of the pile 
within a sound reducing casing. 
In most cases only the pile driver and the top of the pile has been 
enclosed in this way but it has also been proposed to enclose the pile 
driver and pile right down to ground level by means of a box-like 
structure. 
The pile driver in this latter case is permanently housed within the 
structure during use and successive piles to be driven are introduced 
through a door in one wall of the structure. Apart from negligible 
openings in the structure e.g. an aperture in the top surface to allow 
passage of a control cable for the pile driver, the casing completely 
encloses the pile driver and pile. 
According to the present invention, a rig for use in driving and/or 
extracting piles comprises a first sound-reducing enclosure apertured to 
allow a pile to project above the upper surface of said first enclosure, 
and a second sound-reducing enclosure mounted for movement over the top of 
the first enclosure and apertured to accept that portion of the pile 
projecting above the first enclosure. 
Preferably the first enclosure is of a generally elongate shape with its 
length disposed horizontally, and the second enclosure is movable along 
the length of the first enclosure from a region at one end of the first 
enclosure to a region at the other end. In one such embodiment, for 
example, the first enclosure has on its upper surface a track determining 
the line of motion of the second enclosure. 
According to a preferred feature, the second enclosure includes two doors 
adapted to close against one another or to close on the opposite faces of 
a pile adjacent to the pile or piles currently being driven or extracted. 
The second enclosure may be collapsible so as to be able to expand or 
contract vertically as desired. As this allows the pile driver to be 
surrounded always by the same portion of the second enclosure, this 
feature has the advantage of giving maximum effectiveness to any 
additional sound-proofing confined to this portion. Thus in one embodiment 
where the second enclosure has a telescopic construction, the uppermost 
module of the telescopic construction is preferably additionally 
sound-proofed as compared with the other modules of the construction. 
The rig of the present invention is especially suited to use with a row of 
sheet piling and according to another feature of the invention, the rig 
may include, within the volume of the first enclosure, means for 
supporting the piling at the desired inclination (usually upright) during 
at least the topmost part of the motion of the individual piles. 
The support means may, for example, take the form of one or more pairs of 
"gates", the gates of each pair being arranged one on each side of the 
vertical center plane of the rig and movable towards and away from that 
plane. In this latter respect, it is advantageous if at least the upper 
gates can be sufficiently separated to allow the pile driver to pass 
between them if desired.

Referring first to FIGS. 1 and 2, the rig includes a first sound-reducing 
enclosure 10 standing on four ground-supported kelly blocks 12. A 
telescopic second sound-reducing enclosure 14 is mounted for lateral 
movement along the top of the first enclosure. Reference numeral 16 
indicates sheet piling conventionally pitched to form a wall or panel as 
shown. 
The top enclosure 14 is open-ended and the leading face of the enclosure 
includes spring loaded doors 18, 19 (omitted from FIG. 1). This allows the 
top enclosure to embrace the end of the wall 16. Although not apparent 
from FIG. 1 the three modules (21, 22, 23) of the top enclosure carry 
co-operating end flanges which can engage one another so that each module 
is capable of supporting the one below it. A sound-insulating skirt 24, 
such as Revertex Sound Barrier Mat Type JPT 060, secured to the lower edge 
of the top enclosure 14 encapsulates the carriages 42 hereinafter 
described with reference to FIG. 3. If desired, the bottom module can also 
carry a flange at its lower end in case an extra module is to be added 
e.g. for longer piles than previously. 
The enclosure is held expanded by a rope from a light navy crane (not 
shown) attached to lifting points at the top ends of module 21. The crane 
also supports an air hammer (not shown) resting on top of a pile or a pair 
of piles within the enclosure. 
The bottom enclosure 10 includes a largely conventional framework 26, 
surrounded by a sound insulating skirt 28 which has a weighted hem section 
30 engaging the ground to give a good acoustic seal. A suitable material 
for the skirt would be Revertex Sound Barrier Mat Type JPT 060, for 
example, weighted down at the hem section with kentledge. 
In their undriven position, the piles 16 are held upright by two pairs of 
beams 32 to 35 supported on the framework 26 within the bottom enclosure. 
In this embodiment, these beams provide the gates referred to earlier. The 
beams of at least the top pair of beams are preferably horizontally 
displaceable to the positions indicated in chain-dot lines in FIG. 1 to 
allow the piling hammer to pass between them if it is desired to drive the 
top of the piles below the level of these beams. It will be appreciated 
that by the time it is necessary to separate top beams 32, 33 in this way, 
the piles will be sufficiently into the ground to make support of these 
beams unnecessary. 
The arrangement is completed by rails 44 carried by I-beams on the top of 
the lower enclosure and by a decking 29, 31 of rigid sound insulating 
material such as plywood board. The decking seals off the opening 
remaining in the top surface of the lower enclosure after the piles 16 and 
the upper enclosure 14 have been put in position. The central board 29 of 
the decking are made in sections, each section width being equal to one 
traverse of the upper enclosure. As shown in FIG. 1, ahead of the upper 
enclosure, these decking boards are cut to shape to provide a good fit 
around the piles whilst behind the upper enclosure (and beyond the row of 
piles if desired), the central decking boards are provided by single 
pieces. 
It will be observed that in the arrangement illustrated in FIG. 1, the row 
of piles extends practically the whole length of the top enclosure but of 
course the piles must leave enough free track at either end to support the 
top enclosure there when the hammer is engaging the first and last piles 
of the row. 
The operation of the rig is described below with reference to FIG. 1 which 
shows the situation where the upper enclosure 14 is about to begin a 
traverse. Assuming the situation shown in FIG. 1, the piling hammer is 
operated to drive down the pile or piles engaged by the hammer to just 
above the level of the top beams 32, 33. It will be appreciated that the 
hammer will sit on top of the piles throughout the driving operation so 
that its only motion will be downwards movement allowed by the piles as 
they are driven into the ground. The enclosure 14 will also collapse at 
the same rate until it reaches its fully collapsed position when the three 
modules lie wholly one within the other. The pile engaged by the 
springloaded doors referred to earlier is a later pile in the wall than 
the pile or piles engaged by these doors as the top enclosure is collapsed 
during driving. 
When the first piles have been driven down as far as possible with beams 
32, 33 in place, the navy crane is used to raise the hammer and to place 
it on the next pile or piles to be driven. 
When this has been done, the decking 29 associated with the forthcoming 
traverse is removed and the top enclosure (still in its fully collapsed 
state) is moved to the next piles to be driven. The space exposed by this 
movement of the top enclosure is now covered by single-piece decking 29. 
During this traversing motion of the top enclosure, the doors 18, 19 are 
free to move first one way and then the other against the biasing action 
of springs 38, 39 as different parts of the pile profiles are engaged. The 
crane next expands enclosure 14 back to its original height and the 
driving procedure described above can then be repeated. 
Subsequent piles in the row are dealt with in exactly the same way so that 
at the end of its first traverse, the piling hammer has driven all the 
piles enclosed by the bottom enclosure down to just above the level of the 
top beams 32, 33. 
If it is now desired to drive the piles further into the ground, the top 
beams are separated to allow the hammer to pass. Then with the top 
enclosure in its fully collapsed position (and with the doors 18, 19 now 
closing against one another as shown in FIG. 2), the enclosure retraverses 
the row of piles in the reverse direction with the hammer driving in the 
piles to their new depth as it moves along from one location to the next 
with the enclosure. 
One of the advantages of the rig of the present invention is therefore that 
it can be used to achieve a near continuous piling operation from the 
pitched height to the desired level and from end to end of the wall 
section. 
With the driving operation for this section of the piling completed, the 
three modules of the top enclosure are locked together by a shute bolt 
(not shown) to hold the enclosure in its fully collapsed condition. The 
top enclosure is then removed (this time by using lifting points at the 
top end of the centre module 22) and so too is the air hammer. The bottom 
enclosure can now be reassembled around the next section of piling 
enabling the rest of the rig to be set up and operated as before. 
Dismantling and transport present no especial problem since the total 
weight of the rig is only some four tons or so. 
Further details of the rig, described above mostly in general terms, will 
be apparent from FIGS. 2 and 3. Thus FIG. 3 shows a perspective view of a 
carriage 42 which is one of four such carriages supporting the four 
corners of the top enclosure 14. In position, each carriage (not visible 
in FIG. 1) will engage rails 44 carried by I-beams on the top of the lower 
enclosure. 
FIG. 2 shows more clearly the detailed structure of the top enclosure. Each 
module comprises a rigid C-shaped portion (46) closed by the pair of 
sliding doors 18, 19. The height of the modules is about 2.5 meters and 
their plan dimensions vary from 2 .times. 1.6 meters for the inner module 
(21) to 2.6 .times. 2.2 meters for the outer one (23). 
As far as its construction is concerned, the C-shaped part of the inner 
module is formed from a hollow section steel framework internally clad 
with a steel skin. To this skin are welded a number of inwardly projecting 
pins 48 which carry additional sound proofing 50 (also visible in FIG. 1). 
In the illustrated embodiment, this latter takes the form of a wrapping 
fabric 51 filled with fibre glass 52. 
The C-shaped parts of the other two modules also include a hollow section 
steel framework but the internal skin is omitted and the framework is 
externally clad instead with a sound insulating material such as Revertex 
Sound Barrier Mat Type JPT 060. Blocks of sound-reducing material e.g. 
polyurethane foam sheets are secured to the inner surface of the cladding 
in the spaces left between different members of the framework. 
The doors of the three modules are all made of plywood and carry at their 
inside edges rubber sealing strips 54, 55 which will compress slightly 
when they engage a pile. The doors are mounted on runner assemblies (not 
shown) each of which comprises a U-shaped first member secured to the 
leading face of the module, a second member of inverted U-shape secured to 
the door itself, and a number of roller wheels trapped between the two 
members to allow the doors to slide easily from one position to another. 
If desired, the doors can be opened and locked open by a simple system of 
ropes and pulleys (not shown). 
Angle guides 57 welded to the corner edges of modules 22, 23 extend 
upwardly from the bottom two modules by an amount equal to their height. 
These guides are faced with strips 58 of a low friction material (such as 
Nylatron). Nylon pads 59 secured to spacer plates 60 at the corner points 
of modules 21, 22 against the guides prevent excessive lateral movement 
when the enclosure is being telescoped up or down. 
Although an air hammer has been referred to in the specific description, it 
will be appreciated that any other suitable type of pile driving hammer 
could be used instead. Especially suited are those that do not require 
leaders e.g. pneumatic hammers, and steam or diesel driven hammers. Nor is 
the usefulness of the invention restricted to the case where the piles are 
to be driven -- it is equally useful when they are to be extracted and at 
least in its broader aspects, references to driving and to pile drivers 
should not be taken as limiting the invention to exclude its application 
to pile extraction techniques. It should also be understood that the term 
"pile" is not to be narrowly interpreted. The rig of the present invention 
is of course able to accept piles of a wide range of types and 
cross-sections. It should also be borne in mind that the rig could be used 
to drive or extract members other than piles is so desired.