Diesel Hammers: Vulcan Series II Diesel Hammers

First, we need to review what we’ve learned from our previous posts on diesel hammers. First, the posts themselves:

• Diesel Hammers: Rated Striking Energy, and Should Diesel Hammers Be Derated?
• Diesel Hammers: Delmag, Nilens and the Method of Analysis
• Diesel Hammers: The Russian Hammers and Hemi-Headed Pile Drivers
• Diesel Hammers: Pileco

Now we can discuss what we have learned from this analysis:

• The “catch ring stroke” has been on a general upward trend. We can see this from the Delmag D22 (2521 mm) to the Pileco D25-22 (4176 mm.)
• Likewise the thermodynamic energy–and its portion of the “catch ring energy” have increased as well.
• The measured maximum combustion pressures as represented in the database have increased, although the compression ratios have not increased.
• None of the diesel hammers–past or present–can produce the thermodynamic energy necessary to achieve the catch ring stroke. The only way this will take place is if we have rebound or some excessive combustion from a source other than the fuel pump (like this.) It is in reality undesirable for them to do so. It is more difficult to regulate the stroke in a diesel hammer than, say, an external combustion hammer, because of the complex interaction between the ram, the combustion process, the anvil and the pile-soil system; it is the price one pays for the convenience of not having an external power source. In any case when rebound becomes a significant part of the stroke it is because energy being put into the pile-soil system is coming back into the hammer, and thus there is a great deal of energy that is being traded between the ram and the rest of the system. Such energy is not going into pile penetration, which is not good practice either from an equipment standpoint or from a job progress standpoint.

The Vulcan “Series II” Pile Hammers

With its unhappy experience with the diesel hammers it developed in the 1980’s, Vulcan’s objective was to develop a diesel hammer with the following characteristics:

• It wanted a design that was robust, reliable and simple.
• It wanted a design which accommodated U-type leaders.
• It wanted a design that was free of castings. Castings had been Vulcan’s main purchasing challenge–one that came to affect its relations with its customer base–especially during the offshore boom years of the 1970’s and 1980’s. The American foundry system had been in decline throughout that period, a decline that has not stopped to this day. It is difficult to envision building a pile hammer in the U.S. today with the foundry system we have to work with.
• It wanted a hammer with a catch ring stroke that was more comparable with those of Delmag and its Chinese progeny, something that, as we have seen, was on the increase.
• It wanted a design that could be either produced at the Chattanooga facility or one that could be outsourced in other places. The fabricating capabilities of that facility had improved tremendously during the early 1990’s, which made getting away from cast components for a product such as this a possibility. The machining and assembly of such a hammer were well within its capabilities. One option for overseas production was obviously Russia, but the difficulties experienced with the “Series I” made Vulcan management very aware of the difficulties of this option, and in any case Vulcan wasn’t much on outsourcing either its components or products outside of the U.S..
• It wanted a design that it could easily modify if the conditions warranted a modification.

Many within the company did not appreciate the thought process behind commissioning the design of the Series II hammers, let along bringing the Series I into the country.

In any case the specifications for the Series II is given below.

Russian Designation	SO-310	SO-311	SO-312	SO-313	SO-314	SO-315
Vulcan Designation	V13	V19	V25	V35	V50	V75
SI UNITS
Rated Striking Energy, kJ	36.8	55.9	73.5	102.9	147.0	220.5
Minimum Hammer Energy, kJ	18.4	27.9	36.8	51.5	73.5	110.3
Mass of Ram, kg	1,250	1,900	2,500	3,500	5,000	7,500
Maximum Ram Stroke, mm	3,000	3,000	3,000	3,000	3,000	3,000
Number of Blows Per Minute of Ram @ Maximum Stroke	42	42	42	42	42	42
Fuel Capacity, l	12	24	38	78	53	138
Mean Fuel Consumption, l/hr	12	13	12	16	24	35
Mean Oil Consumption, l/hr	0.3	0.3	0.3	0.4	0.5	0.5
Maximum Pile Batter	1:3	1:3	1:3	1:3	1:3	1:3
Total Hammer Mass (including crab), kg	2,750	3,900	5,480	7,720	9,400	16,590
Distance Between Jaws, mm	508	660	660	813	813	940
Width of Jaws, mm	210	235	235	286	286	286
Length, mm	635	775	815	865	865	1,080
Width, mm	700	725	800	953	953	1,100
Height, mm	4,400	4,400	4,980	6,360	5,360	5,840
ENGLISH UNITS
Rated Striking Energy, ft-lbs	27,128	41,235	54,257	75,960	108,514	162,771
Minimum Hammer Energy, ft-lbs	13,564	20,618	27,128	37,980	54,257	81,385
Weight of Ram, lbs.	2,756	4,190	5,513	7,718	11,025	16,538
Maximum Ram Stroke, in.	118	118	118	118	118	118
Number of Blows Per Minute of Ram @ Maximum Stroke	42	42	42	42	42	42
Fuel Capacity (with standard tanks), gal	3	6	10	20	14	36
Mean Fuel Consumption, gal/hr	3	3	3	4	6	9
Mean Oil Consumption, qt/hr	0.3	0.3	0.3	0.4	0.5	0.5
Maximum Pile Batter	1:3	1:3	1:3	1:3	1:3	1:3
Total Hammer Weight (including crab), lbs.	6,064	8,600	12,083	17,023	20,727	36,581
Distance Between Jaws, in.	26	26	26	26	26	26
Width of Jaws, in.	9.25	9.25	9.25	9.25	9.25	9.25
Length, in.	25	31	32	34	34	43
Width, in.	28	29	31	38	38	43
Height, in.	173	173	196	250	211	230

So how would these hammers perform using our analysis? They’re based on the hammers featured in Diesel Hammers: The Russian Hammers and Hemi-Headed Pile Drivers which are, as you can see, variable in their results. One modification possible is to change only two parameters: the combustion chamber volume and the working stroke of the hammer. (They, in turn, affect other parameters as well.) The results of those modifications (which are noted in bold print) are shown below.

Model	SO-310	SO-311	SO-312	SO-313	SO-314	SO-315
Ram mass, kg	1250.0	1900.0	2500	3500	5000	7500
Compression volume, mm3	1784588	3079317	4463529	6034816	7668183	11602960
Ratio of compression volume to ram mass, mm3/kg	1427.7	1620.7	1785.4	1724.2	1533.6	1547.1
Cylinder diameter, mm	300	345	400	470	470	660
Cylinder cross-sectional area, mm2	70686	93482	125664	173494	173494	342119
Probable working stroke from drawings or adjusted working stroke, mm	325	425	425	425	550	425
Actual expansion volume, mm3	24757484	42809174	57870604	79769959	103090132	157003722
Ratio of Free Air Volume to ram mass, mm3/kg	19806	22531	23148	22791	20618	20934
Actual compression ratio	13.9	13.9	13.0	13.2	13.4	13.5
Maximum Physical Stroke, m	3.416	3.390	3.613	3.810	3.810	3.675
Maximum Energy from Maximum Physical Stroke, kJ	41.9	63.2	88.6	130.8	186.9	270.4
Actual Working Volume, m3	0.0230	0.0397	0.0534	0.0737	0.0954	0.1454
Ratio of actual working stroke to cylinder diameter)	1.08	1.23	1.06	0.90	1.17	0.64
Initial Pressure (p1), MPa	0.115	0.115	0.115	0.115	0.115	0.115
Gas Constant k	1.25	1.25	1.25	1.25	1.25	1.25
Compression Pressure (p2), MPa	3.079	3.087	2.829	2.898	2.960	2.985
Maximum Combustion Pressure (p3), MPa	10.00	10.00	10.00	10.00	10.00	10.00
Ratio of Combustion Pressure to Compression Pressure	3.25	3.24	3.53	3.45	3.38	3.35
Total Thermodynamic Energy, kJ	23.805	41.052	60.558	81.521	103.160	155.835
Ratio of Thermodynamic Energy to Maximum Stroke Energy	56.83%	64.97%	68.34%	62.32%	55.20%	57.63%
Mean Effective Pressure from Energy and Actual Working Volume, kPa	1036.241	1033.267	1133.890	1105.595	1081.090	1071.764

The results show parameters such as the compression ratio, the ratio of thermodynamic energy to maximum stroke energy and the mean effective pressure to be in line with newer hammers. All of the working strokes were changed; the only compression volume that was not changed was the SO-315, ironically the only one with a true toroidal combustion chamber. These changed parameters do not consider the secondary geometric effects of their change such as the position of the fuel pump.