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close this bookA Training Manual in Conducting a Workshop in the Design, Construction, Operation, Maintenance and Repair of Hydrams (Peace Corps, 1981, 216 p.)
close this folderSession 16: Use of multiple rams (1½ hours)
View the document(introduction...)
View the documentHandout 16A: Series hydram installation
View the documentHandout 16B: Waste water series hydram installation
View the documentHandout 16C: Parallel hydrams
View the documentHandout 16D: Sample problems


Time 1½ hours


By the end of this session trainees will describe how multiple rams, in series or parallel can be used in situations where h:H ratio, L:D ratio, or D make single ram unpractical or impossible.


In small groups, trainees will solve problems to determine that single ram is impossible, and describe and size multiple system for meeting water need. Large group will discuss advantages/disadvantages of these systems, including cost efficiency.


Handouts 16A, 16B, 16C, 16D

Problems 16A, 16B, 16C on flip chart

Flip charts, markers



1. Introduce session by reviewing limitations of hydram in terms of:

10 min.

- maximum h:H

- L: D ratios

- cost of galvanized pipe in large sizes

State objectives of session.

2. Form 3 small groups and assign each group one problem form Handout 16D. Distribute the relevant diagram (16A, B. or C) to the appropriate group.

The group task is to:

Allow 30 minutes for this.

- solve problem

- determine why single ram will not work

- study diagram and determine why the multiple ram arrangement will work

- size the multiple ram system

- plan 10 minute presentation to the large group

3. Representatives from each group present and answer questions.

30 min.

4. Ask large group to describe any additional advantages/disadvantages of multiple ram systems, any other situation they might be used in.

10 min.

5. Ask participants what application series/parallel rams have at their sites.