1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160 
WHY THIS APATHY TOW, DS ALTERNATIVE FUELS?
Page 86
Page 87
Page 88
If you've noticed an error in this article please click here to report it so we can fix it.
How Official Encouragement Would ' Help in the Development of the Gas-driven Machine. High Cost of Production Militates Against Increased Output of Motor Spirit from Coal WE have, on many previous occasions, commented on the almost complete apathy shown by the Government towards the use of homeproduced fuels, and even at the present time, when the country is in a continual state of anxiety as to what will happen on the morrow, its attitude remains the same.
There are many things it could do, and one which we feel would give immediate impetus to the use of producer-gas machines would be to exclude the weight of the producer and its auxiliaries from the unladen weight of the vehicle, as is done in the case of the batteries on electrically driven machines.
As an example of what this would mean we may take a vehicle weighing over 2i tons, but under 3 tons, unladen, The battery-electric pays £30 in tax, the petrol or oil-engined machine £15, and the equivalent producer-gas outfit £50.
There is a vast amount of research work still to be done in connection with alternative liquid fuels, and the Government should interest itself actively in a project which, by reason of its national character, should not be left to private enterprise.
Little Progress with Liquid Fuels At the present stage of development of the use of liquid fuels, the proposition has not advanced sufficiently to be considered in a practical sense. Vegetable products, we know, provide an almost inexhaustible supply of raw material, but owing to the lack of volatility of fuels derived from such sources they can be burnt only in the high-compression oil engine.
So far, as this country is concerned, coal, unquestionably, forms the most logical line of development and, as is well known, considerable quantities of motor spirit are, at the present time, being produced from this source. In relation to our annual requirements, however, production of motor spirit from coal represents only about 7 per cent., and in view of the costly plant necessary and the comparatively low output for the outlay, it 6Des not seem that we can look in this direction for a practical solution of the problem.
We eau, perhaps, turn to suction gas and town gas as substantial solutions of the alternative-fuel problem, and whilst there are certain known disadvantages attendant upon the employment of such fuels in engines not prinlarily designed for their Lse, steps can be taken so as considerably to reduce this inefficiency factor.
Dealing first of all wit.') the use of town gas, the greatest deterrent undoubtedly lies in the weight of the storage bottles and the difficulty of accommodating them on a normal type of vehicle. Any extended use of town gas for vehicle propulsion would necessitate the setting up of replenishing stations throughout the country, but, no doubt, the supply undertakings would co-operate to this end, if they saw possibilities for the future of this form of fuel.
At the present time the Gas Light and Coke Co has four of its huge fleet of machines running on gas—two Thornycroft 4-tonners and two Albion 7-tonners. The equipment, in all cases, consists of six bottles, which are neatly accommodated lengthwise of the chassis. On the Thornycroft machines there are two bottles on each side of the chassis frame and two inside, towards the rear, and on the Alhions four bottles figure on the near side and two on the off side. In all cases, they are of like capacity, and contain a quantity of gas approximately equivalent to one gallon of motor spirit. So far as the Albion machines are concerned, about six miles' running is obtained per bottle, and with the Thornycrofts about 71 miles'.
In three out of the four vehicles the compression ratio of the engines has been raised, but we understand that there is no difference in the consumption figures, reckoned on a ton-mile basis. Whilst their radius of operation on one filling is somewhat small, they have been in regular daily service for the past nine months and have given excellent service.
Whilst, in town gas, we have a definite and practical means for keeping the wheels turning, the use of a producergas plant is the more practical method for long-distance transport. So far, the sole representative of machines designed specifically to burn producer gas, is found in the Sentinel H.S.G., of which full particulars have already appeared in our columns.
Designed for Producer-gas
The essential differences between the Sentinel H.S.G. and machines converted to the use of producer gas are that the engine capacity is greater for a given chassis tonnage and the producer-gas equipment is incorporated as an integral part of the chassis and not, as must necessarily be the case in conversions, as an afterthought.
In the matters of appearance and performance, therefore, the Sentinel H.S.G. machines need not be different from normal chassis, whilst they have the advantages of economy of operation, characteristic of gas-driven vehicles, and complete independence of imported fuels. During the past two years a number of normal-type petrol chassis has been converted to use producer gas with, it may be said, considerable success. The use of producer gas in machines designed to burn petrol, means a considerable reduction in power and the need for accommodating a somewhat bulky gas-producer unit, and a. filter, of like proportions, in a position found most convenient.
Measures can be taken to compensate for a proportion of the power loss, but, even so, in engines of like capacity, a petrol-gas mixture will give greater power.
Producer-gas Plants Available
There is a number of producer-gas plants available in this country, such as the Koela, Gohin-Poulenc and Dupuy, all of which have proved completely satisfactory when used as conversion units on petrol vehicles, the engines of which have been modified in a way which did not call for extensive structural alterations. One essential modification lies in raising the compression ratio, and this can be done either by using suitable pistons or by taking a little off the jointing face of the cylinder head.
In the case of the Bedford 3-tonner, to which reference was made in our issue dated November 11 last, flat topped pistons replaced a set having concave crowns and 2 mm. was machined off the cylinder head. This procedure raised the compression ratio to S to 1, which is approaching the figure of to 1 set down by authorities as being the limit, beyond which detonation or pre-ignition would take place.
As to the matter of cost, a complete apparatus can be purchased for about £100, to which must be added the cost of installation, which can be taken at about £25.
As in the case of the oil-engined machine, the economic benefits of the producer-gas vehicle cannot be realized to the full unless the minimum mileage be hign, but this question of economy would become of secondary importance should supplies of motor spirit not be available. It is true, however, that the mileage at which net savings begin is lower than in the case of the oil-engined machine and, furthermore, the savings are greater.
The question of suitable fuel is something of a problem, and so far anthra cite beans, low-temperature coke, raw wood, charcoal, charred peat and certain other commodities have been used effectively, but it is essential that this matter of fuel be given some attention if successful results are to he achieved. The producer may be designed to utilize wood fuel, but it is not all woods that are suitable, any more than are all types of anthracite for producers built to consume this fuel.
Although the servicing of a producer-gas vehicle involves operations to which most drivers are unfamiliar, actually 5E it is not so much a question of ASP INLET the difficulty as of unusual character: Filling the hopper with fuel, removing the clinker or cleaning out the pan, and cleaning the filter are operations simple of execution if somewhat more messy than filling up with petrol and, occasionally, cleaning a circuit filter.
The practicability of using either compressed town gas or suction gas having been amply proved, there arises the obvious question as to why operators show little or eo inclination to interest them c3ti selves in these fuels. In the first place, no official encouragement is given, either to makers or users ; a certain amount of prejudice exists with any unorthodox product; conversion plants, at present available, are on the heavy side and the cost is such as to make an operator think twice before making the investment.
Of the foregoing points it is felt that the first is the greatest stumbling block to progress as, apart from granting the gas-driven vehicle a logical tax concession, the Government should interest itself directly in the research work, of which there is still much to be done. The killing of Prejudice is a matter of proving the article and of getting it into general usage, but makers, prompted by past experience, naturally move with considerable circumspection when it comes to the education of operators.
In the matter of weight reduction, considerable savings could be effected by the employment of light metals, particularly for the filter and the leads to and from the producer. It might even be possible to use one of the light alloys for the construction of the producer itself, and herein, it would seem, lies a field for experiment.
The suggested use of light metals could not very well go hand-in-hand with lower cost, but if the weight could be so reduced as to keep a specific type of vehicle within its normal tax category, then its use might be justified. The price factor, however, must always be governed by demand and, until this becomes such as to justify something in the nature of quantity production, the unit cost must naturally remain on the high side.
It is of particular interest to mention that only this week some direct questions were asked in the House relative to the question of producer-gas machines, and it was said that such vehicles were already receiving substantial assistance in that no tax was payable on the fuel and that they also were liable to a lower rate of vehicle tax, at least in the case of the heavier machines.