Part 4 (1/2)

7th Every part accessible for cleaning and repairs

With these points having been deterned This boiler had all the desirable features just enuether with a nueneral form of No 15 was adhered to but the bolted connections between sections and drum and sections and mud druths of boiler tubes expanded into the adjacent parts

This boiler was suspended froirders, like No 15, but these in turn were carried on vertical supports, leaving the pressure parts entirely free fro strains present where one was supported by the other being in this way overcon were built, giving great satisfaction The boiler was known as the ”C I F” (cast-iron front) style, an orna been usually furnished

[Illustration: No 21]

The next step, and the one which connects the boilers as described above to the boiler as it is built to-day, was the design illustrated in No

21 These boilers were known as the ”W I F” style, the fronts furnished as part of the equipht iron The cast-iron drued and ”buer and the sections connected to wrought-steel cross boxes riveted to the bottoirders and columns as in No 20

[Illustration: No 22]

No 22 This boiler, which is designated as the ”Vertical Header” type, has the saeneral features of construction as No 21, except that the tube sheet side of the headers is ”stepped” to allow the headers to be placed vertically and at right angles to the drule used in Nos 20 and 21

[Illustration: No 23]

No 23, or the cross drun of boiler, is a development of the Babcock & Wilcox marine boiler, in which the cross druow Works of The Babcock & Wilcox, Ltd, with No 18 proved that proper attention to details of construction would make it a most desirable fore nuiving satisfactory results under widely varying conditions The cross drun

Boilers Nos 21, 22 and 23, with a few ns are illustrated, as they are constructed to-day, on pages 48, 52, 54, 58 and 60

The last step in the development of the water-tube boiler, beyond which it seems almost impossible for science and skill to advance, consists in the ht steel, including sinuous headers, cross boxes, nozzles, and the like This construction was the result of the deeneral vogue in this country The Babcock & Wilcox Co have at the present tis that have been pronounced by the _London Engineer_ to be ”a perfect triuns of this all wrought-steel boiler are fully illustrated in the following pages

[Illustration: Wrought-steel Vertical Header Longitudinal Drum Babcock & Wilcox Boiler, Equipped with Babcock & Wilcox Superheater and Babcock & Wilcox Chain Grate Stoker]

THE BABcock & WILcox BOILER

The following brief description of the Babcock & Wilcox boiler will clearly indicate the manner in which it fulfills the requirements of the perfect steam boiler already enumerated

The Babcock & Wilcox boiler is built in two general classes, the longitudinal druns may be constructed with vertical or inclined headers, and the headers in turn ht steel or cast iron dependent upon the working pressure for which the boiler is constructed The headers ths, that is, e in the nuht per section and the number of sections in width that the size of the boiler is varied

The longitudinal druenerally accepted standard of Babcock & Wilcox construction The cross druned to meet certain conditions of headroom, has become popular for numerous classes of here low headroom is not a requirement whichsurface of this type of boiler isupon the width of the boiler extending longitudinally over the other pressure parts To the druh cross boxes at either end the sections, which are made up of headers and tubes At the lower end of the sections there is aand connected to all sections The connections between all parts are by short lengths of tubes expanded into bored seats

[Illustration: Forged-steel Drumhead with Manhole Plate in Position]

The druive the required factor of safety under the maximum pressure for which the boiler is constructed The circular seah these may be double lap riveted to meet certain requireitudinal seams are properly proportioned butt and strap or lap riveted joints dependent upon the pressure for which the boilers are built Where butt strap joints are used the straps are bent to the proper radius in an hydraulic press The courses are built independently to te press All riveted holes are punched one-quarter inch smaller than the size of rivets as driven and are reamed to full size after the plates are assembled All rivets are driven by hydraulic pressure and held until black

[Illustration: Forged-steel Drued at a single heat, the ed in position Flat raised seats for water colu

All heads are provided with es of which are turned true The ed steel and turned to fit ed-steel guards and bolts