“MONORAIL” — MONORAIL BEAM ANALYSIS
Program Description:
“MONORAIL” is a spreadsheet program written in MS-Excel for the purpose of analysis of either S-shape or
W-shape underhung monorail beams analyzed as simple-spans with or without overhangs (cantilevers).
Specifically, the x-axis and y-axis bending moments as well as any torsion effects are calculated. The actual and
allowable stresses are determined, and the effect of lower flange bending is also addressed by two different
approaches.
This program is a workbook consisting of three (3) worksheets, described as follows:
Worksheet Name Description
Doc This documentation sheet
S-shaped Monorail Beam Monorail beam analysis for S-shaped beams
W-shaped Monorail Beam Monorail beam analysis for W-shaped beams
Program Assumptions and Limitations:
- The following references were used in the development of this program:
a. Fluor Enterprises, Inc. – Guideline 000.215.1257 – “Hoisting Facilities” (August 22, 2005)
b. Dupont Engineering Design Standard: DB1X – “Design and Installation of Monorail Beams” (May 2000)
c. American National Standards Institute (ANSI): MH27.1 – “Underhung Cranes and Monorail Syatems”
d. American Institute of Steel Construction (AISC) 9th Edition Allowable Stress Design (ASD) Manual (1989)
e. “Allowable Bending Stresses for Overhanging Monorails” – by N. Stephen Tanner –
AISC Engineering Journal (3rd Quarter, 1985)
f. Crane Manufacturers Association of America, Inc. (CMAA) – Publication No. 74 –
“Specifications for Top Running & Under Running Single Girder Electric Traveling Cranes
Utilizing Under Running Trolley Hoist” (2004)
g. “Design of Monorail Systems” – by Thomas H. Orihuela Jr., PE (www.pdhengineer.com)
h. British Steel Code B.S. 449, pages 42-44 (1959)
i. USS Steel Design Manual – Chapter 7 “Torsion” – by R. L. Brockenbrough and B.G. Johnston (1981)
j. AISC Steel Design Guide Series No. 9 – “Torsional Analysis of Structural Steel Members” –
by Paul A. Seaburg, PhD, PE and Charlie J. Carter, PE (1997)
k. “Technical Note: Torsion Analysis of Steel Sections” – by William E. Moore II and Keith M. Mueller –
AISC Engineering Journal (4th Quarter, 2002) - The unbraced length for the overhang (cantilever) portion, ‘Lbo’, of an underhung monorail beam is often debated.
The following are some recommendations from the references cited above:
a. Fluor Guideline 000.215.1257: Lbo = Lo+L/2
b. Dupont Standard DB1X: Lbo = 3Lo c. ANSI Standard MH27.1: Lbo = 2Lo
d. British Steel Code B.S. 449: Lbo = 2Lo (for top flange of monorail beam restrained at support) British Steel Code B.S. 449: Lbo = 3Lo (for top flange of monorail beam unrestrained at support)
e. AISC Eng. Journal Article by Tanner: Lbo = Lo+L (used with a computed value of ‘Cbo’ from article) - This program also determines the calculated value of the bending coefficient, ‘Cbo’, for the overhang (cantilever)
portion of the monorail beam from reference “e” in note #1 above. This is located off of the main calculation page.
Note: if this computed value of ‘Cbo’ is used and input, then per this reference the total value of Lo+L should be
used for the unbraced length, ‘Lbo’, for the overhang portion of the monorail beam. - This program ignores effects of axial compressive stress produced by any longitudinal (traction) force which is
usually considered minimal for underhung, hand-operated monorail systems. - This program contains “comment boxes” which contain a wide variety of information including explanations of
input or output items, equations used, data tables, etc. (Note: presence of a “comment box” is denoted by a
“red triangle” in the upper right-hand corner of a cell. Merely move the mouse pointer to the desired cell to view
the contents of that particular “comment box”.)
